Enhanced foam fractionation of oil phase from aqueous/oil mixed phase via increased viscoelasticity

ABSTRACT

The present invention provides improved methods for purifying and/or removing oily particles, and/or contaminants suspended or dissolved in water. In particular the process relates to an additive composition that has the appropriate surfactant characteristics for effectively removing an oil phase from an oil/aqueous mixed phase via foam fractionation. According to the invention, a hydrophobically modified polymer that acts as an associative thickener is combined with surfactant in appropriate ratios to facilitate oil removal for water purification in any of a number of commercial, environmental and industrial applications.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional application of non-provisional U.S.Ser. No. 13/791,276, filed Mar. 8, 2013, which is hereby incorporated byreference in its entirety.

FIELD OF THE INVENTION

The present invention provides improved methods for purifying and/orremoving oily particles, and/or contaminants suspended or dissolved inwater. In particular the process relates to an additive composition thathas the appropriate surfactant characteristics for effectively removingan oil phase from an oil/aqueous mixed phase via foam fractionation. Thefoam fractionation techniques and additives may be used to remove oiland oily soils in any of a number of water purification embodiments oilspill removal, purification of waste water and the like.

BACKGROUND OF THE INVENTION

Foam fractionation is a chemical process in which hydrophobic moleculesare preferentially separated from a liquid solution using rising columnsof air bubbles, with a resulting foam layer on top of the solutiontrapping the hydrophobic molecule. In general two mechanisms provide foreffective removal of molecules from a solution, first a target moleculeadsorbs to a bubble surface, and then the bubbles travel up a column andform a foam layer on top which can be collected and disposed of.

Foam fractionation predominantly removes surfactant contaminantmolecules (molecules that have polar and non-polar ends). At theair-water interface of the bubbles the surfactant molecules orientatethemselves so that the non-polar hydrophobic end of the surfactantmolecules is in air and the polar hydrophilic end of the molecule is inwater. As the bubbles rise to the top of the fractionating column theyremove the contaminants and settle at the top of the column as a foam.

Many organic substances can be removed by foam fractionation and largerbiological material, such as algae, bacteria and viruses can also beremoved. Particles present in the water can also be removed. It isthought that biological material and particles become trapped in thefilm surrounding the air bubbles. Inorganic material can also be removedif it can form some kind of a bond with organic matter in the water. Forexample, calcium carbonate and calcium phosphate complexes can collectorganic matter in the water forming micro-flocs that can get trapped inthe film surrounding the air bubbles. Metal ions can also form ligandswith organic molecules, and glycoproteins have a high affinity for tracemetals and therefore facilitate removal of metal ion species from water.Foam fractionation to date has encountered many difficulties when usedin removing oil from an oil/aqueous mixed phase.

Efficient contaminant removal is complex and depends on many factorsincluding air to water ratio; column height; air bubble diameter;air/water contact time; air bubble flow rate; foaming agent; foamwetness; downward water flow rate; foam stability; and collision speedbetween the water and the rising gas. Foam stability is also animportant factor and can be defined as the resistance to contaminantdrainage from the foam, without foam rupturing. The foam must be stableenough to be removed from the fractionating column, without leaching ofthe contaminant molecules into the water occurring. The most widely usedfoaming agent cocamide DEA, or cocamide diethanolamine, has come underregulatory pressure and the International Agency for Research on Cancer(IARC) lists coconut oil diethanolamine condensate (cocamide DEA) as anIARC Group 2B carcinogen, which identifies this chemical as possiblycarcinogenic to humans.

The use of surfactants, such as soap and synthetic detergents, fordissolving organic compounds, is well known in the art. Particularly,surfactant is applied to hydrophobic organic compounds (chemicalsubstances which have a very low solubility in water) for the purposeeither dissolving, emulsifying or dispersing the organic compounds in awater environment. Another particular property of surfactant moleculeswhich may be related to solubilization is aggregation to sub-microndroplets, referred to in the art as micelles. In a water environment,the surfactant molecules constituting the micelle are oriented with thehydrophilic heads towards the water, i.e., outwards, and the hydrophobictails towards the interior of the micelle. Consequently, the micelle'sinterior is a hydrophobic micro-environment, capable of retainingorganic solutes.

It is also well known to separate surfactant micelles from water bymeans of an ultrafiltration mechanism. Foam fractionation may also beused. According to this mechanism, liquids containing surfactants may bepurified by passing a gas through the liquid, thereby generating a foam.The foam is collected and condensed by means of a mechanical foambreaker. The method is suitable for purifying dilute surfactantsolutions, since the concentration of surfactant in the foam is higherthan in the original liquid.

Accordingly it is an object herein to provide a foam fractionationmethod that does not employ the use of cocamide DEA.

It is yet another object of the invention to provide a compositionemploying a surfactant platform that can be used with foam fractionationto remove oil and other grease suspended or dissolved in the same.

Other objects, aspects and advantages of this invention will be apparentto one skilled in the art in view of the following disclosure, thedrawings, and the appended claims.

SUMMARY OF THE INVENTION

The invention involves the discovery of the appropriate polymer andsurfactant package to enhance foam fractionation of oil from aqueous/oilmixed phase. According to the invention, the polymer used is preferablyhydrophobically modified, and is an associative thickener. The type ofsurfactant is not critical and any surfactant can be used, althoughnonionic is preferred. The surfactant may be present in the additivecomposition or may be already present in the aqueous/oil mixed phaseitself.

According to the invention, oil removal compositions are formed with aneffective amount of an associative thickener in the presence of asurfactant which may already be present. In an additive composition theassociative thickener is present in a ratio of greater than 1:1 ofassociative thickener to surfactant on a weight basis and may be presentin a ratio of 2:1, 3:1, 4:1 and even up to 5:1.

In some embodiments, the composition also includes additional optionaldetersive ingredients; wherein the compositions are substantially freeof cocamide DEA. Other surfactants and standard cleaning compositioncomponents may also be included as well.

A novel cleaning method is also within the scope of the invention andinvolves separating the surfactant/oil mixture from the solution by foamfractionation. In particular, the mixture is transferred to a suitablefoam fractionation column, through which a continuous bubbling of gas issupplied in a counter-current flow. Suitable gases for bubbling includeair, nitrogen and carbon dioxide. The gas bubbles carry thesurfactant/oil aggregate as a foam into an overhead chamber that isequipped with a mechanical foam breaker to condense the foam.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 shows the absorbance of the treated water at 0 through 4additions. One can see that after 4 additions, the absorbance units aregreatly reduced. Blue=control, red=one addition, pink=2 additions,green=3 additions, yellow=4 additions.

FIG. 2 shows the captured total suspended solids as passed through afilter. One can see that after 3 additions, the filter isindistinguishable from a clean filter. The foam fractionation removedmultiply charged cations, hydrocarbons, proteins and carbonate.

FIG. 3 is a graph showing FOG reduction with the composition of theinvention at 0 to 3 additions. One can see that the FOG starts at 30.2and after 3 additions is down to 2.9 or 1.4.

FIG. 4 is a graph of absorbance and wave number of the particulates inthe water. After 3 additions, the total suspended solids are reduced tobaseline levels, showing near complete removal of hydrocarbon, protein,and carbonate.

FIG. 5 shows the design of a foam fractionator that may be used inaccordance with the invention and which was used in the experimentsreported in the Examples section.

FIG. 6 is a diagram showing the foam fractionation process.

FIGS. 7A and 7B show different types of foam fractionators that can beused according to the invention.

FIGS. 8A and 8B show that the invention works with various levels of airintroduction for each system.

FIG. 9 is a graph showing the transmittance over time with addition ofthe compositions of the invention.

FIG. 10 is a graph of percent transmittance over time with theassociative thickeners of 44 ppm Rheomer 33, 44 ppm Acusol, and 45 ppmNovethix L-10.

FIG. 11 is a graph of the data below, showing percent transmittance overtime for different combinations of polymer and ash.

FIG. 12 is a graph of transmittance over time for Rheomer 33 alone andafter addition of the surfactant.

DETAILED DESCRIPTION OF THE INVENTION

The present invention aims to provide improved waterpurification/treatment or cleaning compositions and methods forpurifying and/or removing particles, and/or contaminants suspended ordissolved in water. The invention is primarily directed at removing anoil phase from an oil/aqueous mixed phase via foam fractionation. Thefoam fractionation techniques and additives may be used to remove oiland oily soils in any of a number of water purification and cleaningembodiments such as pot and pan soaking compositions, hand soaps, foamfractionation, gas exploration water removal, food and beverage foamingcleaners, vehicle cleaning, oil spill clean-up and the like.

The compositions and methods of the invention may be used independentlyor be combined with other water treatment methods and apparatus such asa screen or drum filter and an ultraviolet light treatment unit forwater treatment purposes.

While the presently described technology will be described in connectionwith one or more preferred embodiments, it will be understood by thoseskilled in the art that the technology is not limited to only thoseparticular embodiments. To the contrary, the presently describedtechnology includes all alternatives, modifications, and equivalents asmay be included within the spirit and scope of the appended claims.The term “water” as used throughout the specification includescontaminated water or any other water or liquid carrying oil based orother impurities.

“Cleaning” means to perform or aid in soil removal, bleaching, microbialpopulation reduction, rinsing, or combination thereof.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a composition containing “a compound” includes a mixture oftwo or more compounds. It should also be noted that the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

The term “actives” or “percent actives” or “percent by weight actives”or “actives concentration” are used interchangeably herein and refers tothe concentration of those ingredients involved in cleaning expressed asa percentage minus inert ingredients such as water or salts.

As used herein, “weight percent,” “wt. %,” “percent by weight,” “% byweight,” and variations thereof refer to the concentration of asubstance as the weight of that substance divided by the total weight ofthe composition and multiplied by 100. It is understood that, as usedhere, “percent,” “%,” and the like are intended to be synonymous with“weight percent,” “wt. %,” etc.

The term “about,” as used herein, modifying the quantity of aningredient in the compositions of the invention or employed in themethods of the invention refers to variation in the numerical quantitythat can occur, for example, through typical measuring and liquidhandling procedures used for making concentrates or use solutions;through inadvertent error in these procedures; through differences inthe manufacture, source, or purity of the ingredients employed to makethe compositions or carry out the methods; and the like. The term“about” also encompasses amounts that differ due to differentequilibrium conditions for a composition resulting from a particularinitial mixture. Whether or not modified by the term “about,” the claimsinclude equivalents to the quantities. All numeric values are hereinassumed to be modified by the term “about,” whether or not explicitlyindicated. The term “about” generally refers to a range of numbers thatone of skill in the art would consider equivalent to the recited value(i.e., having the same function or result). In many instances, the terms“about” may include numbers that are rounded to the nearest significantfigure.

The recitation of numerical ranges by endpoints includes all numberssubsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4, and 5).

The terms “include” and “including” when used in reference to a list ofmaterials refer to but are not limited to the materials so listed.

The term “water soluble” refers to a compound that can be dissolved inwater at a concentration of more than 1 wt. %. The terms “sparinglysoluble” or “sparingly water soluble” refer to a compound that can bedissolved in water only to a concentration of 0.1 to 1.0 wt. %. The term“water insoluble” refers to a compound that can be dissolved in wateronly to a concentration of less than 0.1 wt. %.

The term “surfactant” as used herein is a compound that contains alipophilic segment and a hydrophilic segment, which when added to wateror solvents, reduces the surface tension of the system.

An “extended chain surfactant” is a surfactant having an intermediatepolarity linking chain, such as a block of poly-propylene oxide, or ablock of poly-ethylene oxide, or a block of poly-butylene oxide or amixture thereof inserted between the surfactant's conventionallipophilic segment and hydrophilic segment.

According to the invention foam fractionation may be combined with otherwater purification techniques such as ultrafiltration to remove andparticulate matters.

Compositions of the Invention

Associative Thickener

The compositions and methods of the invention employ the use ofassociative thickeners in combination with surfactants for foamfractionation. Associative thickeners are thickeners which have beenknown for many years and are intended for aqueous systems. They areused, inter alia, in dispersion-bound water-based paints and finishesbut also other aqueous systems, for example cleaning agents, cosmetics,pickles, aqueous pigment pastes, automotive finishes, industrialcoatings, printing inks, lubricating greases, plaster paints and wallpaints, textile coatings, pharmaceutical preparations, crop protectionformulations, filler dispersions, adhesives, detergents, waxdispersions, polishes, auxiliaries for tertiary mineral oil productionetc., are adjusted rheologically therewith.

The typical mode of action of these thickeners is due to their chemicalcomposition. In general, associative thickeners consist of awater-soluble hydrophilic main part, i.e. a water-soluble polymer chainwhich for the most part comprises polyethylene glycol or comprisescellulose derivatives, acrylate chains, polyether chains or polyesterchains, hydrophobic groups being attached to these polymer chains. Thetwo parts are bound to one another on a very wide range of types ofcovalent bonds. The link here can be affected, for example, by urethanebonds, ester bonds, ether bonds, urea bonds, carbonate bonds or amidebonds.

The customary preparation of the associative thickeners is effected byreacting, for example, bifunctional alcohols (usually polyethyleneglycol) with bifunctional reactants (usually diisocyanates) in apolyaddition reaction and terminating the addition reaction by addingmonofunctional reactants (e.g. monofunctional alcohols, such asnonylphenol ethoxylate). The hydrophobic groups required for theformation of the associative interaction are then present as terminalgroups bonded to the water-soluble polymer chain.

The hydrophilic moiety remains dissolved in the aqueous phase in theapplication system. The hydrophobic groups, however, accumulate athydrophobic surfaces, for example on the dispersed or emulsified organicbinders in an aqueous coating, for example an emulsion paint, on thehydrophobic surfaces of fillers, pigments, etc. Since a thickenerpolymer usually has two terminal (or a plurality of additional)hydrophobic moieties, it may link simultaneously to a plurality ofdispersion particles. These are linked to one another with the aid ofthe hydrophilic base chain. It forms as a result of a thickening effectwhich is based on the association of the hydrophobic or of the lesswater-soluble moieties and the build-up of a three-dimensional networkby means of van der Waals' interaction in the aqueous system. Anassociative thickener is referred to here as having a structuralviscosity (A) if its solution viscosity in 20% strength aqueous solutionis more than 100 000 mPas and the viscosity in the Acronal test systemat a shear rate of 1 sec⁻¹ is more than 10 000 mPas (for thismeasurement, 16% by weight of butyldiglycol, as a viscosity-reducingsubstance, is added to the associative thickener having a structuralviscosity, in order for it to be processable: 20% by weight ofthickener+16% by weight of butyldiglycol+64% by weight of water).

One example of a commercially available associative thickener is Acusol820 available from Dow Chemical, Midland Mich., a hydrophobicallymodified alkali soluble acrylic polymer Emulsion (HASE). Otherassociative thickeners include Sokalan AT 120 (a methacrylicacid/acrylic acid copolymer) available from BASF; Sokalan HP 25 (amodified polycarboxylate) also available from BASF; Rheomer® 33 (ahydrophobically-modified alkali swellable emulsion polymer) availablefrom Rhodia/Solvay; Novethix™ L-10 polymer (a hydrophoically modifiedalkali-swellable emulsion polymer) available from Lubrizol, and PolygelHP available from 3V company. One example of a commercially availablenonionic associative thickener is Pluraflo AT-301 available from BASF,with a 3 armed EO-PO polyether backbone capped with long alkyl chains.Other commercially available nonionic associative thickeners include PEG150 disterate, supplied as Rewopol PEG 6000 DS from Evonik, PEG 6000 DSfrom Stepan, and Cremophor DS 150 from BASF; PEG 120 methyl glucosedioleate supplied as Glucamate DOE-120 from Lubrizol; and PEG-120 methylglucose trioleate supplied as Glucamate LT from Lubrizol.

According to the invention, an associative thickener is added to theoil/aqueous mixture then the mixture is subjected to foam fractionation.Surfactant may be present already in the aqueous mixture, or may beadded as a composition combined with the associative thickener. Whenprovided as an additive composition, the associative thickener andsurfactant are present in the composition in a ratio of greater than 1:1by weight of associative thickener to surfactant. The ratio can go ashigh as 2:1, 3:1, 4:1 or even 5:1.

Surfactants

The methods and compositions of the invention comprise a surfactant orin some cases an additional surfactant. As indicated earlier, surfactantmay already be present in the oil/aqueous composition, and may includethe addition of further surfactant to achieve the desired ratio, or maybe admixed with the associative thickener to form an additivecomposition that is added to the aqueous oil composition in an effectiveamount to remove oil via foam fractionation. Surfactants include watersoluble or water dispersible nonionic, semi-polar nonionic (supra),anionic, cationic, amphoteric, or zwitterionic surface-active agents;viscoelastic surfactants or any combination thereof. A typical listingof the classes and species of surfactants useful herein appears in U.S.Pat. No. 3,664,961 issued May 23, 1972, to Norris.

Nonionic Surfactants

The surfactant is preferably a nonionic surfactant. Nonionic surfactantsuseful in the invention are generally characterized by the presence ofan organic hydrophobic group and an organic hydrophilic group and aretypically produced by the condensation of an organic aliphatic, alkylaromatic or polyoxyalkylene hydrophobic compound with a hydrophilicalkaline oxide moiety which in common practice is ethylene oxide or apolyhydration product thereof, polyethylene glycol. Practically anyhydrophobic compound having a hydroxyl, carboxyl, amino, or amino groupwith a reactive hydrogen atom can be condensed with ethylene oxide, orits polyhydration adducts, or its mixtures with alkoxylenes such aspropylene oxide to form a nonionic surface-active agent. The length ofthe hydrophilic polyoxyalkylene moiety which is condensed with anyparticular hydrophobic compound can be readily adjusted to yield a waterdispersible or water soluble compound having the desired degree ofbalance between hydrophilic and hydrophobic properties. Useful nonionicsurfactants in the present invention include:

1. Block polyoxypropylene-polyoxyethylene polymeric compounds based uponpropylene glycol, ethylene glycol, glycerol, trimethylolpropane, andethylenediamine as the initiator reactive hydrogen compound. Examples ofpolymeric compounds made from a sequential propoxylation andethoxylation of initiator are commercially available under the tradenames Pluronic® and Tetronic® manufactured by BASF Corp.

Pluronic® compounds are difunctional (two reactive hydrogens) compoundsformed by condensing ethylene oxide with a hydrophobic base formed bythe addition of propylene oxide to the two hydroxyl groups of propyleneglycol. This hydrophobic portion of the molecule weighs from 1,000 to4,000. Ethylene oxide is then added to sandwich this hydrophobe betweenhydrophilic groups, controlled by length to constitute from about 10% byweight to about 80% by weight of the final molecule.

Tetronic® compounds are tetra-functional block copolymers derived fromthe sequential addition of propylene oxide and ethylene oxide toethylenediamine. The molecular weight of the propylene oxide hydrotyperanges from 500 to 7,000; and, the hydrophile, ethylene oxide, is addedto constitute from 10% by weight to 80% by weight of the molecule.

2. Condensation products of one mole of alkyl phenol wherein the alkylchain, of straight chain or branched chain configuration, or of singleor dual alkyl constituent, contains from 8 to 18 carbon atoms with from3 to 50 moles of ethylene oxide. The alkyl group can, for example, berepresented by diisobutylene, di-amyl, polymerized propylene, iso-octyl,nonyl, and di-nonyl. These surfactants can be polyethylene,polypropylene, and polybutylene oxide condensates of alkyl phenols.Examples of commercial compounds of this chemistry are available on themarket under the trade names Igepal® manufactured by Rhone-Poulenc andTriton® manufactured by Union Carbide.

3. Polyethylene sorbitan fatty acid esters with the esterifying fattyacid being selected from the group consisting of C₁₂-C.₁₈ fatty acidswherein an average of about 1 or 3 of said acids are esterified perpolyoxyethylene sorbitan molecule. One preferred non-ionic surfactant isa mixture of laurate esters of sorbitol and sorbitol anhydrides(sorbitan) consisting predominantly of the mono-ester condensed withabout 20 moles of ethylene oxide. This surfactant is designated in theCTFA dictionary as Polysorbate 20 and is also known in the art aspolyoxyethylene (20) sorbitan monolaurate and is available from severalcommercial sources. Another suitable example of a polyoxyethylene alkylester is the CTFA designated Polysorbate 80 which is a mixture of oleateesters of sorbitol and sorbitol anhydrides, condensed with approximately80 moles of ethylene oxide. In a preferred embodiment the surfactant isan ethoxylated sorbitan ester. In another preferred embodiment thesurfactant is a sorbitan ester without the polyoxyethylene groups.

4. Condensation products of one mole of a saturated or unsaturated,straight or branched chain alcohol having from 6 to 24 carbon atoms withfrom 3 to 50 moles of ethylene oxide. The alcohol moiety can consist ofmixtures of alcohols in the above delineated carbon range or it canconsist of an alcohol having a specific number of carbon atoms withinthis range. Examples of like commercial surfactant are available underthe trade names Neodol® manufactured by Shell Chemical Co. and Alfonic®manufactured by Vista Chemical Co.

5. Condensation products of one mole of saturated or unsaturated,straight or branched chain carboxylic acid having from 8 to 18 carbonatoms with from 6 to 50 moles of ethylene oxide. The acid moiety canconsist of mixtures of acids in the above defined carbon atoms range orit can consist of an acid having a specific number of carbon atomswithin the range. Examples of commercial compounds of this chemistry areavailable on the market under the trade names Nopalcol® manufactured byHenkel Corporation and Lipopeg® manufactured by Lipo Chemicals, Inc.

In addition to ethoxylated carboxylic acids, commonly calledpolyethylene glycol esters, other alkanoic acid esters formed byreaction with glycerides, glycerin, and polyhydric (saccharide orsorbitan/sorbitol) alcohols have application in this invention. All ofthese ester moieties have one or more reactive hydrogen sites on theirmolecule which can undergo further acylation or ethylene oxide(alkoxide) addition to control the hydrophilicity of these substances.

Examples of Nonionic Low Foaming Surfactants Include:

6. Compounds from (1) which are modified, essentially reversed, byadding ethylene oxide to ethylene glycol to provide a hydrophile ofdesignated molecular weight; and, then adding propylene oxide to obtainhydrophobic blocks on the outside (ends) of the molecule. Thehydrophobic portion of the molecule weighs from 1,000 to 3,100 with thecentral hydrophile including 10% by weight to 80% by weight of the finalmolecule. These reverse Pluronics® are manufactured by BASF Corporationunder the trade name Pluronic® R surfactants.

Likewise, the Tetronic® R surfactants are produced by BASF Corporationby the sequential addition of ethylene oxide and propylene oxide toethylenediamine. The hydrophobic portion of the molecule weighs from2,100 to 6,700 with the central hydrophile including 10% by weight to80% by weight of the final molecule.

7. Compounds from groups (1), (2), (3) and (4) which are modified by“capping” or “end blocking” the terminal hydroxy group or groups (ofmulti-functional moieties) to reduce foaming by reaction with a smallhydrophobic molecule such as propylene oxide, butylene oxide, benzylchloride; and, short chain fatty acids, alcohols or alkyl halidescontaining from 1 to 5 carbon atoms; and mixtures thereof. Also includedare reactants such as thionyl chloride which convert terminal hydroxygroups to a chloride group. Such modifications to the terminal hydroxygroup may lead to all-block, block-heteric, heteric-block or all-hetericnonionics.

Additional examples of effective low foaming nonionics include:

8. The alkylphenoxypolyethoxyalkanols of U.S. Pat. No. 2,903,486 issuedSep. 8, 1959 to Brown et al. and represented by the formula

in which R is an alkyl group of 8 to 9 carbon atoms, A is an alkylenechain of 3 to 4 carbon atoms, n is an integer of 7 to 16, and m is aninteger of 1 to 10.

The polyalkylene glycol condensates of U.S. Pat. No. 3,048,548 issuedAug. 7, 1962 to Martin et al. having alternating hydrophilic oxyethylenechains and hydrophobic oxypropylene chains where the weight of theterminal hydrophobic chains, the weight of the middle hydrophobic unitand the weight of the linking hydrophilic units each represent aboutone-third of the condensate.

The defoaming nonionic surfactants disclosed in U.S. Pat. No. 3,382,178issued May 7, 1968 to Lissant et al. having the general formulaZ[(OR)_(n)OH]_(z) wherein Z is alkoxylatable material, R is a radicalderived from an alkaline oxide which can be ethylene and propylene and nis an integer from, for example, 10 to 2,000 or more and z is an integerdetermined by the number of reactive oxyalkylatable groups.

The conjugated polyoxyalkylene compounds described in U.S. Pat. No.2,677,700, issued May 4, 1954 to Jackson et al. corresponding to theformula Y(C₃H₆O)_(n)(C₂H₄O)_(m)H wherein Y is the residue of organiccompound having from 1 to 6 carbon atoms and one reactive hydrogen atom,n has an average value of at least 6.4, as determined by hydroxyl numberand m has a value such that the oxyethylene portion constitutes 10% to90% by weight of the molecule.

The conjugated polyoxyalkylene compounds described in U.S. Pat. No.2,674,619, issued Apr. 6, 1954 to Lundsted et al. having the formulaY[(C₃H₆O_(n)(C₂H₄O)_(m)H]_(x) wherein Y is the residue of an organiccompound having from 2 to 6 carbon atoms and containing x reactivehydrogen atoms in which x has a value of at least 2, n has a value suchthat the molecular weight of the polyoxypropylene hydrophobic base is atleast 900 and m has value such that the oxyethylene content of themolecule is from 10% to 90% by weight. Compounds falling within thescope of the definition for Y include, for example, propylene glycol,glycerine, pentaerythritol, trimethylolpropane, ethylenediamine and thelike. The oxypropylene chains optionally, but advantageously, containsmall amounts of ethylene oxide and the oxyethylene chains alsooptionally, but advantageously, contain small amounts of propyleneoxide.

Additional conjugated polyoxyalkylene surface-active agents which areadvantageously used in the compositions of this invention correspond tothe formula: P[(C₃H₆O)_(n)(C₂H₄O)_(m)H]_(x) wherein P is the residue ofan organic compound having from 8 to 18 carbon atoms and containing xreactive hydrogen atoms in which x has a value of 1 or 2, n has a valuesuch that the molecular weight of the polyoxyethylene portion is atleast 44 and m has a value such that the oxypropylene content of themolecule is from 10% to 90% by weight. In either case the oxypropylenechains may contain optionally, but advantageously, small amounts ofethylene oxide and the oxyethylene chains may contain also optionally,but advantageously, small amounts of propylene oxide.

9. Polyhydroxy fatty acid amide surfactants suitable for use in thepresent compositions include those having the structural formulaR²CONR¹Z in which: R¹ is H, C₁-C₄ hydrocarbyl, 2-hydroxy ethyl,2-hydroxy propyl, ethoxy, propoxy group, or a mixture thereof; R is aC₅-C₃1 hydrocarbyl, which can be straight-chain; and Z is apolyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3hydroxyls directly connected to the chain, or an alkoxylated derivative(preferably ethoxylated or propoxylated) thereof. Z can be derived froma reducing sugar in a reductive amination reaction; such as a glycitylmoiety.

10. The alkyl ethoxylate condensation products of aliphatic alcoholswith from 0 to 25 moles of ethylene oxide are suitable for use in thepresent compositions. The alkyl chain of the aliphatic alcohol caneither be straight or branched, primary or secondary, and generallycontains from 6 to 22 carbon atoms.

11. The ethoxylated C₆-C₁₈ fatty alcohols and C₆-C₁₈ mixed ethoxylatedand propoxylated fatty alcohols are suitable surfactants for use in thepresent compositions, particularly those that are water soluble.Suitable ethoxylated fatty alcohols include the C₁₀-C₁₈ ethoxylatedfatty alcohols with a degree of ethoxylation of from 3 to 50.

12. Suitable nonionic alkylpolysaccharide surfactants, particularly foruse in the present compositions include those disclosed in U.S. Pat. No.4,565,647, Llenado, issued Jan. 21, 1986. These surfactants include ahydrophobic group containing from 6 to 30 carbon atoms and apolysaccharide, e.g., a polyglycoside, hydrophilic group containing from1.3 to 10 saccharide units. Any reducing saccharide containing 5 or 6carbon atoms can be used, e.g., glucose, galactose and galactosylmoieties can be substituted for the glucosyl moieties. (Optionally thehydrophobic group is attached at the 2-, 3-, 4-, etc. positions thusgiving a glucose or galactose as opposed to a glucoside or galactoside.)The intersaccharide bonds can be, e.g., between the one position of theadditional saccharide units and the 2-, 3-, 4-, and/or 6-positions onthe preceding saccharide units.

13. Fatty acid amide surfactants suitable for use in the presentcompositions include those having the formula: R⁶CON(R⁷)₂ in which R⁶ isan alkyl group containing from 7 to 21 carbon atoms and each R⁷ isindependently hydrogen, C₁-C₄ alkyl, C₁-C₄ hydroxyalkyl, or—(C₂H₄O)_(x)H, where x is in the range of from 1 to 3.

14. A useful class of non-ionic surfactants includes the class definedas alkoxylated amines or, most particularly, alcoholalkoxylated/aminated/alkoxylated surfactants. These non-ionicsurfactants may be at least in part represented by the general formulae:

R²⁰—(PO)_(s)N-(EO)_(t) H,

R²0-(PO)_(s)N-(EO)_(t)H(EO)_(t)H, and

R²⁰—N(EO)_(t)H;

in which R²⁰ is an alkyl, alkenyl or other aliphatic group, or analkyl-aryl group of from 8 to 20, preferably 12 to 14 carbon atoms, EOis oxyethylene, PO is oxypropylene, s is 1 to 20, preferably 2-5, t is1-10, preferably 2-5, and u is 1-10, preferably 2-5. Other variations onthe scope of these compounds may be represented by the alternativeformula:

R²⁰—(PO)_(v)—N[(EO)_(w)H][(EO)_(z)H]

in which R²⁰ is as defined above, v is 1 to 20 (e.g., 1, 2, 3, or 4(preferably 2)), and w and z are independently 1-10, preferably 2-5.

These compounds are represented commercially by a line of products soldby Huntsman Chemicals as nonionic surfactants. A preferred chemical ofthis class includes Surfonic™ PEA 25 Amine Alkoxylate.

The treatise Nonionic Surfactants, edited by Schick, M. J., Vol. 1 ofthe Surfactant Science Series, Marcel Dekker, Inc., New York, 1983 is anexcellent reference on the wide variety of nonionic compounds generallyemployed in the practice of the present invention. A typical listing ofnonionic classes, and species of these surfactants, is given in U.S.Pat. No. 3,929,678 issued to Laughlin and Heuring on Dec. 30, 1975.Further examples are given in “Surface Active Agents and Detergents”(Vol. I and II by Schwartz, Perry and Berch).

Semi-Polar Nonionic Surfactants

The semi-polar type of nonionic surface active agents was describedsupra.

Anionic Surfactants

Also useful in the present invention are surface active substances whichare categorized as anionics because the charge on the hydrophobe isnegative; or surfactants in which the hydrophobic section of themolecule carries no charge unless the pH is elevated to neutrality orabove (e.g. carboxylic acids). Carboxylate, sulfonate, sulfate andphosphate are the polar (hydrophilic) solubilizing groups found inanionic surfactants. Of the cations (counter ions) associated with thesepolar groups, sodium, lithium and potassium impart water solubility;ammonium and substituted ammonium ions provide both water and oilsolubility; and, calcium, barium, and magnesium promote oil solubility.As those skilled in the art understand, anionics are excellent detersivesurfactants and are therefore favored additions to heavy duty detergentcompositions. Generally, however, anionics have high foam profiles whichlimit their use alone or at high concentration levels in cleaningsystems such as CIP circuits that require strict foam control. Anionicsurface active compounds are useful to impart special chemical orphysical properties other than detergency within the composition.Anionics can be employed as gelling agents or as part of a gelling orthickening system. Anionics are excellent solubilizers and can be usedfor hydrotropic effect and cloud point control.

The majority of large volume commercial anionic surfactants can besubdivided into five major chemical classes and additional sub-groupsknown to those of skill in the art and described in “SurfactantEncyclopedia,” Cosmetics & Toiletries, Vol. 104 (2) 71-86 (1989). Thefirst class includes acylamino acids (and salts), such as acylgluamates,acyl peptides, sarcosinates (e.g. N-acyl sarcosinates), taurates (e.g.N-acyl taurates and fatty acid amides of methyl tauride), and the like.The second class includes carboxylic acids (and salts), such as alkanoicacids (and alkanoates), ester carboxylic acids (e.g. alkyl succinates),ether carboxylic acids, and the like. The third class includes sulfonicacids (and salts), such as isethionates (e.g. acyl isethionates),alkylaryl sulfonates, alkyl sulfonates, sulfosuccinates (e.g. monoestersand diesters of sulfosuccinate), and the like. The fifth class includessulfuric acid esters (and salts), such as alkyl ether sulfates, alkylsulfates, and the like.

Anionic sulfate surfactants suitable for use in the present compositionsinclude the linear and branched primary and secondary alkyl sulfates,alkyl ethoxysulfates, fatty oleyl glycerol sulfates, alkyl phenolethylene oxide ether sulfates, the C₅-C₁₇ acyl-N—(C₁-C₄ alkyl) and—N—(C₁-C₂ hydroxyalkyl)glucamine sulfates, and sulfates ofalkylpolysaccharides such as the sulfates of alkylpolyglucoside (thenonionic nonsulfated compounds being described herein).

Examples of suitable synthetic, water soluble anionic detergentcompounds include the ammonium and substituted ammonium (such as mono-,di- and triethanolamine) and alkali metal (such as sodium, lithium andpotassium) salts of the alkyl mononuclear aromatic sulfonates such asthe alkyl benzene sulfonates containing from 5 to 18 carbon atoms in thealkyl group in a straight or branched chain, e.g., the salts of alkylbenzene sulfonates or of alkyl toluene, xylene, cumene and phenolsulfonates; alkyl naphthalene sulfonate, diamyl naphthalene sulfonate,and dinonyl naphthalene sulfonate and alkoxylated derivatives.

Anionic carboxylate surfactants suitable for use in the presentcompositions include the alkyl ethoxy carboxylates, the alkyl polyethoxypolycarboxylate surfactants and the soaps (e.g. alkyl carboxyls).Secondary soap surfactants (e.g. alkyl carboxyl surfactants) useful inthe present compositions include those which contain a carboxyl unitconnected to a secondary carbon. The secondary carbon can be in a ringstructure, e.g. as in p-octyl benzoic acid, or as in alkyl-substitutedcyclohexyl carboxylates. The secondary soap surfactants typicallycontain no ether linkages, no ester linkages and no hydroxyl groups.Further, they typically lack nitrogen atoms in the head-group(amphiphilic portion). Suitable secondary soap surfactants typicallycontain 11-13 total carbon atoms, although more carbons atoms (e.g., upto 16) can be present.

Other anionic detergents suitable for use in the present compositionsinclude olefin sulfonates, such as long chain alkene sulfonates, longchain hydroxyalkane sulfonates or mixtures of alkenesulfonates andhydroxyalkane-sulfonates. Also included are the alkyl sulfates, alkylpoly(ethyleneoxy)ether sulfates and aromatic poly(ethyleneoxy)sulfatessuch as the sulfates or condensation products of ethylene oxide andnonyl phenol (usually having 1 to 6 oxyethylene groups per molecule).Resin acids and hydrogenated resin acids are also suitable, such asrosin, hydrogenated rosin, and resin acids and hydrogenated resin acidspresent in or derived from tallow oil.

The particular salts will be suitably selected depending upon theparticular formulation and the needs therein.

Further examples of suitable anionic surfactants are given in “SurfaceActive Agents and Detergents” (Vol. I and II by Schwartz, Perry andBerch). A variety of such surfactants are also generally disclosed inU.S. Pat. No. 3,929,678, issued Dec. 30, 1975 to Laughlin, et al. atColumn 23, line 58 through Column 29, line 23.

Cationic Surfactants

Surface active substances are classified as cationic if the charge onthe hydrotrope portion of the molecule is positive. Surfactants in whichthe hydrotrope carries no charge unless the pH is lowered close toneutrality or lower, but which are then cationic (e.g. alkyl amines),are also included in this group. In theory, cationic surfactants may besynthesized from any combination of elements containing an “onium”structure RnX+Y— and could include compounds other than nitrogen(ammonium) such as phosphorus (phosphonium) and sulfur (sulfonium). Inpractice, the cationic surfactant field is dominated by nitrogencontaining compounds, probably because synthetic routes to nitrogenouscationics are simple and straightforward and give high yields ofproduct, which can make them less expensive.

Cationic surfactants preferably include, more preferably refer to,compounds containing at least one long carbon chain hydrophobic groupand at least one positively charged nitrogen. The long carbon chaingroup may be attached directly to the nitrogen atom by simplesubstitution; or more preferably indirectly by a bridging functionalgroup or groups in so-called interrupted alkylamines and amino amines.Such functional groups can make the molecule more hydrophilic and/ormore water dispersible, more easily water solubilized by co-surfactantmixtures, and/or water soluble. For increased water solubility,additional primary, secondary or tertiary amino groups can be introducedor the amino nitrogen can be quaternized with low molecular weight alkylgroups. Further, the nitrogen can be a part of branched or straightchain moiety of varying degrees of unsaturation or of a saturated orunsaturated heterocyclic ring. In addition, cationic surfactants maycontain complex linkages having more than one cationic nitrogen atom.

The surfactant compounds classified as amine oxides, amphoterics andzwitterions are themselves typically cationic in near neutral to acidicpH solutions and can overlap surfactant classifications.Polyoxyethylated cationic surfactants generally behave like nonionicsurfactants in alkaline solution and like cationic surfactants in acidicsolution.

The simplest cationic amines, amine salts and quaternary ammoniumcompounds can be schematically drawn thus:

in which, R represents a long alkyl chain, R′, R″, and R′ may be eitherlong alkyl chains or smaller alkyl or aryl groups or hydrogen and Xrepresents an anion. The amine salts and quaternary ammonium compoundsare preferred for practical use in this invention due to their highdegree of water solubility.

The majority of large volume commercial cationic surfactants can besubdivided into four major classes and additional sub-groups known tothose of skill in the art and described in “Surfactant Encyclopedia,”Cosmetics & Toiletries, Vol. 104 (2) 86-96 (1989). The first classincludes alkylamines and their salts. The second class includes alkylimidazolines. The third class includes ethoxylated amines. The fourthclass includes quaternaries, such as alkylbenzyldimethylammonium salts,alkyl benzene salts, heterocyclic ammonium salts, tetra alkylammoniumsalts, and the like. Cationic surfactants are known to have a variety ofproperties that can be beneficial in the present compositions. Thesedesirable properties can include detergency in compositions of or belowneutral pH, antimicrobial efficacy, thickening or gelling in cooperationwith other agents, and the like.

Cationic surfactants useful in the compositions of the present inventioninclude those having the formula R¹ _(m)R² _(x)YLZ wherein each R¹ is anorganic group containing a straight or branched alkyl or alkenyl groupoptionally substituted with up to three phenyl or hydroxy groups andoptionally interrupted by up to four of the following structures:

or an isomer or mixture of these structures, and which contains from 8to 22 carbon atoms. The R¹ groups can additionally contain up to 12ethoxy groups. m is a number from 1 to 3. Preferably, no more than oneR¹ group in a molecule has 16 or more carbon atoms when m is 2, or morethan 12 carbon atoms when m is 3. Each R² is an alkyl or hydroxyalkylgroup containing from 1 to 4 carbon atoms or a benzyl group with no morethan one R² in a molecule being benzyl, and x is a number from 0 to 11,preferably from 0 to 6. The remainder of any carbon atom positions onthe Y group is filled by hydrogens.Y can be a group including, but not limited to:

or a mixture thereof.

Preferably, L is 1 or 2, with the Y groups being separated by a moietyselected from R¹ and R² analogs (preferably alkylene or alkenylene)having from 1 to 22 carbon atoms and two free carbon single bonds when Lis 2. Z is a water soluble anion, such as sulfate, methylsulfate,hydroxide, or nitrate anion, particularly preferred being sulfate ormethyl sulfate anions, in a number to give electrical neutrality of thecationic component.

Amphoteric Surfactants

Amphoteric, or ampholytic, surfactants contain both a basic and anacidic hydrophilic group and an organic hydrophobic group. These ionicentities may be any of the anionic or cationic groups described hereinfor other types of surfactants. A basic nitrogen and an acidiccarboxylate group are the typical functional groups employed as thebasic and acidic hydrophilic groups. In a few surfactants, sulfonate,sulfate, phosphonate or phosphate provide the negative charge.

Amphoteric surfactants can be broadly described as derivatives ofaliphatic secondary and tertiary amines, in which the aliphatic radicalmay be straight chain or branched and wherein one of the aliphaticsubstituents contains from 8 to 18 carbon atoms and one contains ananionic water solubilizing group, e.g., carboxy, sulfo, sulfato,phosphato, or phosphono. Amphoteric surfactants are subdivided into twomajor classes known to those of skill in the art and described in“Surfactant Encyclopedia,” Cosmetics & Toiletries, Vol. 104 (2) 69-71(1989). The first class includes acyl/dialkyl ethylenediaminederivatives (e.g. 2-alkyl hydroxyethyl imidazoline derivatives) andtheir salts. The second class includes N-alkylamino acids and theirsalts. Some amphoteric surfactants can be envisioned as fitting intoboth classes.

Amphoteric surfactants can be synthesized by methods known to those ofskill in the art. For example, 2-alkyl hydroxyethyl imidazoline issynthesized by condensation and ring closure of a long chain carboxylicacid (or a derivative) with dialkyl ethylenediamine. Commercialamphoteric surfactants are derivatized by subsequent hydrolysis andring-opening of the imidazoline ring by alkylation—for example withethyl acetate. During alkylation, one or two carboxy-alkyl groups reactto form a tertiary amine and an ether linkage with differing alkylatingagents yielding different tertiary amines.

Long chain imidazole derivatives having application in the presentinvention generally have the general formula:

wherein R is an acyclic hydrophobic group containing from 8 to 18 carbonatoms and M is a cation to neutralize the charge of the anion, generallysodium. Commercially prominent imidazoline-derived amphoterics that canbe employed in the present compositions include for example:Cocoamphopropionate, Cocoamphocarboxy-propionate, Cocoamphoglycinate,Cocoamphocarboxy-glycinate, Cocoamphopropyl-sulfonate, andCocoamphocarboxy-propionic acid. Preferred amphocarboxylic acids areproduced from fatty imidazolines in which the dicarboxylic acidfunctionality of the amphodicarboxylic acid is diacetic acid and/ordipropionic acid.

The carboxymethylated compounds (glycinates) described herein abovefrequently are called betaines. Betaines are a special class ofamphoteric discussed herein below in the section entitled, ZwitterionSurfactants.

Long chain N-alkylamino acids are readily prepared by reacting RNH₂, inwhich R.dbd.C₈-C₁₈ straight or branched chain alkyl, fatty amines withhalogenated carboxylic acids. Alkylation of the primary amino groups ofan amino acid leads to secondary and tertiary amines. Alkyl substituentsmay have additional amino groups that provide more than one reactivenitrogen center. Most commercial N-alkylamine acids are alkylderivatives of beta-alanine or beta-N(2-carboxyethyl) alanine. Examplesof commercial N-alkylamino acid ampholytes having application in thisinvention include alkyl beta-amino dipropionates, RN(C₂H₄COOM)₂ andRNHC₂H₄COOM. In these, R is preferably an acyclic hydrophobic groupcontaining from 8 to 18 carbon atoms, and M is a cation to neutralizethe charge of the anion.

Preferred amphoteric surfactants include those derived from coconutproducts such as coconut oil or coconut fatty acid. The more preferredof these coconut derived surfactants include as part of their structurean ethylenediamine moiety, an alkanolamide moiety, an amino acid moiety,preferably glycine, or a combination thereof; and an aliphaticsubstituent of from 8 to 18 (preferably 12) carbon atoms. Such asurfactant can also be considered an alkyl amphodicarboxylic acid.Disodium cocoampho dipropionate is one most preferred amphotericsurfactant and is commercially available under the tradename Miranol™FBS from Rhodia Inc., Cranbury, N.J. Another most preferred coconutderived amphoteric surfactant with the chemical name disodium cocoamphodiacetate is sold under the tradename Miranol C2M-SF Conc., also fromRhodia Inc., Cranbury, N.J.

A typical listing of amphoteric classes, and species of thesesurfactants, is given in U.S. Pat. No. 3,929,678 issued to Laughlin andHeuring on Dec. 30, 1975. Further examples are given in “Surface ActiveAgents and Detergents” (Vol. I and II by Schwartz, Perry and Berch).

Zwitterionic Surfactants

Zwitterionic surfactants can be thought of as a subset of the amphotericsurfactants. Zwitterionic surfactants can be broadly described asderivatives of secondary and tertiary amines, derivatives ofheterocyclic secondary and tertiary amines, or derivatives of quaternaryammonium, quaternary phosphonium or tertiary sulfonium compounds.Typically, a zwitterionic surfactant includes a positive chargedquaternary ammonium or, in some cases, a sulfonium or phosphonium ion, anegative charged carboxyl group, and an alkyl group. Zwitterionicsgenerally contain cationic and anionic groups which ionize to a nearlyequal degree in the isoelectric region of the molecule and which candevelop strong “inner-salt” attraction between positive-negative chargecenters. Examples of such zwitterionic synthetic surfactants includederivatives of aliphatic quaternary ammonium, phosphonium, and sulfoniumcompounds, in which the aliphatic radicals can be straight chain orbranched, and wherein one of the aliphatic substituents contains from 8to 18 carbon atoms and one contains an anionic water solubilizing group,e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Betaineand sultaine surfactants are exemplary zwitterionic surfactants for useherein.

A general formula for these compounds is:

wherein R1 contains an alkyl, alkenyl, or hydroxyalkyl radical of from 8to 18 carbon atoms having from 0 to 10 ethylene oxide moieties and from0 to 1 glyceryl moiety; Y is selected from the group consisting ofnitrogen, phosphorus, and sulfur atoms; R.sup.2 is an alkyl ormonohydroxy alkyl group containing 1 to 3 carbon atoms; x is 1 when Y isa sulfur atom and 2 when Y is a nitrogen or phosphorus atom, R³ is analkylene or hydroxy alkylene or hydroxy alkylene of from 1 to 4 carbonatoms and Z is a radical selected from the group consisting ofcarboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.

Examples of zwitterionic surfactants having the structures listed aboveinclude:4-[[N,N-di(2-hydroxyethyl)-N-octadecylammonio]-butane-1-car-boxylate;5-1S-3-hydroxypropyl-S-hexadecylsulfonio]-3-hydroxypentane-1-sul-fate;3-[P,P-diethyl-P-3,6,9-trioxatetracosanephosphonio]-2-hydroxypropane--1-phosphate;3-[N,N-dipropyl-N-3-dodecoxy-2-hydroxypropyl-ammonio]-propan-e-1-phosphonate;3-(N,N-dimethyl-N-hexadecylammonio)-propane-1-sulfonate;3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxy-propane-1-sulfonate;4-[N,N-di(2(2-hydroxyethyl)-N(2-hydroxydodecyl)ammonio]-butane-1-carboxyl-ate;3-[S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio]-propane-1-phosphat-e;3-[P,P-dimethyl-P-dodecylphosphonio]-propane-1-phosphonate; and S[N,N-di(3-hydroxypropyl)-N-hexadecylammonio]-2-hydroxy-pentane-1-sulfate.The alkyl groups contained in said detergent surfactants can be straightor branched and saturated or unsaturated.

The zwitterionic surfactant suitable for use in the present compositionsincludes a betaine of the general structure:

These surfactant betaines typically do not exhibit strong cationic oranionic characters at pH extremes nor do they show reduced watersolubility in their isoelectric range. Unlike “external” quaternaryammonium salts, betaines are compatible with anionics. Examples ofsuitable betaines include coconut acylamidopropyldimethyl betaine;hexadecyl dimethyl betaine; C₁₂₋₁₄ acylamidopropylbetaine; C₈₋₁₄acylamidohexyldiethyl betaine; 4-C₁₄₋₁₆acylmethylamidodiethylammonio-1-carboxybutane; C₁₆₋₁₈acylamidodimethylbetaine; C₁₂₋₁₆ acylamidopentanediethylbetaine; andC₁₂₋₁₆ acylmethylamidodimethylbetaine.

Sultaines useful in the present invention include those compounds havingthe formula (R(R1)₂N.sup.+R²SO³—, in which R is a C₆-C₁₈ hydrocarbylgroup, each R¹ is typically independently C₁-C₃ alkyl, e.g. methyl, andR² is a C₁-C₆ hydrocarbyl group, e.g. a C₁-C₃ alkylene orhydroxyalkylene group.

A typical listing of zwitterionic classes, and species of thesesurfactants, is given in U.S. Pat. No. 3,929,678 issued to Laughlin andHeuring on Dec. 30, 1975. Further examples are given in “Surface ActiveAgents and Detergents” (Vol. I and II by Schwartz, Perry and Berch).

The composition of additional surfactant can be present in the range ofapproximately 0-10000 ppm in cleaning solutions at use concentrations.

Viscoelastic Surfactants

In some embodiments, the surfactant is a viscoelastic surfactant.Viscoelastic surfactants may comprise any number of different compounds,including methyl ester sulfonates (e.g., as described in U.S. patentapplication Ser. Nos. 11/058,660, 11/058,475, 11/058,612, and11/058,611, filed Feb. 15, 2005, the relevant disclosures of which areincorporated herein by reference), hydrolyzed keratin (e.g., asdescribed in U.S. Pat. No. 6,547,871, the relevant disclosure of whichis incorporated herein by reference), sulfosuccinates, taurates, amineoxides, ethoxylated amides, alkoxylated fatty acids, alkoxylatedalcohols (e.g., lauryl alcohol ethoxylate, ethoxylated nonyl phenol),ethoxylated fatty amines, ethoxylated alkyl amines (e.g., cocoalkylamineethoxylate), betaines, modified betaines, alkylamidobetaines (e.g.,cocoamidopropyl betaine), quaternary ammonium compounds (e.g.,trimethyltallowammonium chloride, trimethylcocoammonium chloride),derivatives thereof, and finally, polyethyleleneimin (PEI) and itsderivatives, including ethoxylated PEI and combinations of any of theforegoing. The term “derivative” is defined herein to include anycompound that is made from one of the listed compounds, for example, byreplacing one atom in the listed compound with another atom or group ofatoms, rearranging two or more atoms in the listed compound, ionizingthe listed compounds, or creating a salt of the listed compound.

The aqueous viscoelastic surfactant may be based on amphoteric orzwitterionic surfactants.

The amphoteric surfactant is a class of surfactant that has both apositively charged moiety and a negatively charged moiety over a certainpH range (e.g. typically slightly acidic), only a negatively chargedmoiety over a certain pH range (e.g. typically slightly alkaline) andonly a positively charged moiety at a different pH range (e.g. typicallymoderately acidic), while a zwitterionic surfactant has a permanentlypositively charged moiety in the molecule regardless of pH and anegatively charged moiety at alkaline pH. Examples of zwitterionicsurfactants useful in the present invention are represented by theformula:

wherein R₁ represents a hydrophobic moiety of alkyl, alkylarylalkyl,alkoxyalkyl, alkylaminoalkyl and alkylamidoalkyl, wherein alkylrepresents a group that contains from about 12 to about 24 carbon atomswhich may be branched or straight chained and which may be saturated orunsaturated. Representative long chain alkyl groups include tetradecyl(myristyl), hexadecyl (cetyl), octadecentyl (oleyl), octadecyl(stearyl), docosenoic (erucyl) and the derivatives of tallow, coco, soyaand rapeseed oils. The preferred alkyl and alkenyl groups are alkyl andalkenyl groups having from about 16 to about 22 carbon atoms.Representative of alkylamidoalkyl is alkylamidopropyl with alkyl beingas described above. R² and R³ are independently an aliphatic chain (i.e.as opposed to aromatic at the atom bonded to the quaternary nitrogen,e.g., alkyl, alkenyl, arylalkyl, hydroxyalkyl, carboxyalkyl, andhydroxyalkyl-polyoxyalkylene, e.g. hydroxyethyl-polyoxyethylene orhydroxypropyl-polyoxypropylene) having from 1 to about 30 atoms,preferably from about 1 to about 20 atoms, more preferably from about 1to about 10 atoms and most preferably from about 1 to about 6 atoms inwhich the aliphatic group can be branched or straight chained, saturatedor unsaturated. Preferred alkyl chains are methyl, ethyl, preferredarylalkyl is benzyl, and preferred hydroxyalkyls are hydroxyethyl orhydroxypropyl, while preferred carboxyalkyls are acetate and propionate.R4 is a hydrocarbyl radical (e.g. alkylene) with chain length 1 to 4.Preferred are methylene or ethylene groups.

Specific examples of zwitterionic surfactants include the followingstructures:

wherein R₁ has been previously defined herein.Examples of amphoteric surfactants include those represented by formulaVI:

wherein R₁, R₂, and R₄ are the same as defined above.

Other specific examples of amphoteric surfactants include the followingstructures:

wherein R₁ has been previously defined herein, and X⁺ is an inorganiccation such as Na⁺, K⁺, NH₄ ⁺ associated with a carboxylate group orhydrogen atom in an acidic medium.

Suitable viscoelastic surfactants may comprise mixtures of severaldifferent compounds, including but not limited to: mixtures of anammonium salt of an alkyl ether sulfate, a cocoamidopropyl betainesurfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodiumchloride, and water; mixtures of an ammonium salt of an alkyl ethersulfate surfactant, a cocoamidopropyl hydroxysultaine surfactant, acocoamidopropyl dimethylamine oxide surfactant, sodium chloride, andwater; mixtures of an ethoxylated alcohol ether sulfate surfactant, analkyl or alkene amidopropyl betaine surfactant, and an alkyl or alkenedimethylamine oxide surfactant; aqueous solutions of an alpha-olefinicsulfonate surfactant and a betaine surfactant; and combinations thereof.Examples of suitable mixtures of an ethoxylated alcohol ether sulfatesurfactant, an alkyl or alkene amidopropyl betaine surfactant, and analkyl or alkene dimethylamine oxide surfactant are described in U.S.Pat. No. 6,063,738, the relevant disclosure of which is incorporatedherein by reference. Examples of suitable aqueous solutions of analpha-olefinic sulfonate surfactant and a betaine surfactant aredescribed in U.S. Pat. No. 5,879,699, the relevant disclosure of whichis incorporated herein by reference. Suitable viscoelastic surfactantsalso may comprise “catanionic” surfactant systems, which comprise pairedoppositely-charged surfactants that act as counterions to each other andmay form wormlike micelles. Examples of such catanionic surfactantsystems include, but are not limited to sodium oleate (NaO)/octyltrimethylammonium chloride (C₈TAC) systems, stearyl trimethylammoniumchloride (C₁₈TAC)/caprylic acid sodium salt (NaCap) systems, and cetyltrimethylammonium tosylate (CTAT)/sodium dodecylbenzenesulfonate (SDBS)systems.

Examples of commercially-available viscoelastic surfactants suitable foruse in the present invention may include, but are not limited to,Mirataine BET-O 30™ (an oleamidopropyl betaine surfactant available fromRhodia Inc., Cranbury, N.J.), DV-8829 a erucicdimethylamidopropylbetaineC₂₉H₅₇N₂O₃ ⁻ Surfactant available from Rhodia Inc., Cranbury, N.J.,Aromox APA-T (amine oxide surfactant available from Akzo NobelChemicals, Chicago, Ill.), Ethoquad O/12 PG™ (a fatty amine ethoxylatequat surfactant available from Akzo Nobel Chemicals, Chicago, Ill.),Ethomeen T/12™ (a fatty amine ethoxylate surfactant available from AkzoNobel Chemicals, Chicago, Ill.), Ethomeen S/12™ (a fatty amineethoxylate surfactant available from Akzo Nobel Chemicals, Chicago,Ill.), and Rewoteric AM TEG™ (a tallow dihydroxyethyl betaine amphotericsurfactant available from Degussa Corp., Parsippany, N.J.).

Typical chemical processes for synthesizing viscoelastic surfactants aredisclosed in U.S. Pat. No. 6,258,858 the disclosure of which is hereinincorporated by reference.

Extended Surfactants

Extended chain surfactants having an intermediate polarity linkingchain, such as a block of poly-propylene oxide, or a block ofpoly-butylene oxide or a mixture thereof inserted between thesurfactant's conventional lipophilic segment and hydrophilic segment.The extended surfactants can commonly be either nonionic or anionic.

In a preferred embodiment the surfactant is one or more of sorbitanmonolaurate, sorbitan monostearate, sorbitan monooleate, POE (20)sorbitan monolaurate, POE (20) sorbitan monostearate, and POE (20)sorbitan monooleate.

As indicated earlier, the associative thickener may be added directly tothe oil/aqueous phase solution to be subjected to foam fractionationwhen surfactant is already present in the solution. The amount ofassociative thickener and any needed additional surfactant are simplyadded to the solution to achieve the desired ratio of greater than 1:1by weight of associative thickener to surfactant. In another embodiment,the associative thickener and surfactant may be combined in a cleaningcomposition at appropriate ratios to be added to the aqueous solution.

The compositions may also include additional materials, such asadditional functional materials, for example enzymes, enzyme stabilizingsystem, additional surfactant, chelating agents, sequestering agents,bleaching agents, thickening agent, solubility modifier, filler,anti-redeposition agent, a threshold agent or system, aestheticenhancing agent (i.e. dye, perfume, etc.) and the like, or combinationsor mixtures thereof. Adjuvants and other additive ingredients will varyaccording to the type of composition being manufactured and can beincluded in the compositions in any amount. The following is a briefdiscussion of some examples of such additional materials.

Water Conditioning Agent

A water conditioning agent aids in removing metal compounds and inreducing harmful effects of hardness components in service water.Exemplary water conditioning agents include chelating agents,sequestering agents and inhibitors. Polyvalent metal cations orcompounds such as a calcium, a magnesium, an iron, a manganese, amolybdenum, etc. cation or compound, or mixtures thereof, can be presentin service water and in complex soils. Such compounds or cations caninterfere with the effectiveness of a washing or rinsing compositionsduring a cleaning application. A water conditioning agent caneffectively complex and remove such compounds or cations from soiledsurfaces and can reduce or eliminate the inappropriate interaction withactive ingredients including the nonionic surfactants and anionicsurfactants of the invention. Both organic and inorganic waterconditioning agents are common and can be used. Inorganic waterconditioning agents include such compounds as sodium tripolyphosphateand other higher linear and cyclic polyphosphates species. Organic waterconditioning agents include both polymeric and small molecule waterconditioning agents. Organic small molecule water conditioning agentsare typically organocarboxylate compounds or organophosphate waterconditioning agents. Polymeric inhibitors commonly comprise polyanioniccompositions such as polyacrylic acid compounds. Small molecule organicwater conditioning agents include, but are not limited to: sodiumgluconate, sodium glucoheptonate, N-hydroxyethylenediaminetriacetic acid(HEDTA), ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid(NTA), diethylenetriaminepentaacetic acid (DTPA),ethylenediaminetetraproprionic acid, triethylenetetraaminehexaaceticacid (TTHA), and the respective alkali metal, ammonium and substitutedammonium salts thereof, ethylenediaminetetraacetic acid tetrasodium salt(EDTA), nitrilotriacetic acid trisodium salt (NTA), ethanoldiglycinedisodium salt (EDG), diethanolglycine sodium-salt (DEG), and1,3-propylenediaminetetraacetic acid (PDTA), dicarboxymethyl glutamicacid tetrasodium salt (GLDA), methylglycine-N—N-diacetic acid trisodiumsalt (MGDA), and iminodisuccinate sodium salt (IDS). All of these areknown and commercially available.

The composition of a water conditioning agent can be present in therange of approximately 0-5000 ppm in cleaning solutions at useconcentrations.

Anti-Redeposition Agents

The composition may include an anti-redeposition agent capable offacilitating sustained suspension of soils in a cleaning solution andpreventing the removed soils from being redeposited onto the substratebeing cleaned. Examples of suitable antiredeposition agents includefatty acid amides, fluorocarbon surfactants, complex phosphate esters,styrene maleic anhydride copolymers, and the like.

The composition of an anti-redeposition agent can be present in therange of approximately 0-5000 ppm in cleaning solutions at useconcentrations.

Hydrotrope

The compositions of the invention may optionally include a hydrotrope,coupling agent, or solubilizer that aides in compositional stability,and aqueous formulation. Functionally speaking, the suitable couplerswhich can be employed are non-toxic and retain the active ingredients inaqueous solution throughout the temperature range and concentration towhich a concentrate or any use solution is exposed.

Any hydrotrope coupler may be used provided it does not react with theother components of the composition or negatively affect the performanceproperties of the composition. Representative classes of hydrotropiccoupling agents or solubilizers which can be employed include anionicsurfactants such as alkyl sulfates and alkane sulfonates, linear alkylbenzene or naphthalene sulfonates, secondary alkane sulfonates, alkylether sulfates or sulfonates, alkyl phosphates or phosphonates, dialkylsulfosuccinic acid esters, sugar esters (e.g., sorbitan esters), amineoxides (mono-, di-, or tri-alkyl) and C₈-C₁₀ alkyl glucosides. Preferredcoupling agents for use in the present invention includen-octanesulfonate, available as NAS 8D from Ecolab Inc., n-octyldimethylamine oxide, and the commonly available aromatic sulfonates suchas the alkyl benzene sulfonates (e.g. xylene sulfonates) or naphthalenesulfonates, aryl or alkaryl phosphate esters or their alkoxylatedanalogues having 1 to about 40 ethylene, propylene or butylene oxideunits or mixtures thereof. Other preferred hydrotropes include nonionicsurfactants of C₆-C₂₄ alcohol alkoxylates (alkoxylate means ethoxylates,propoxylates, butoxylates, and co-or-terpolymer mixtures thereof)(preferably C₆-C₁₄ alcohol alkoxylates) having 1 to about 15 alkyleneoxide groups (preferably about 4 to about 10 alkylene oxide groups);C₆-C₂₄ alkylphenol alkoxylates (preferably C₈-C₁₀ alkylphenolalkoxylates) having 1 to about 15 alkylene oxide groups (preferablyabout 4 to about 10 alkylene oxide groups); C₆-C₂₄ alkylpolyglycosides(preferably C₆-C₂₀ alkylpolyglycosides) having 1 to about 15 glycosidegroups (preferably about 4 to about 10 glycoside groups); C₆-C₂₄ fattyacid ester ethoxylates, propoxylates or glycerides; and C₄-C₁₂ mono ordialkanolamides.

The composition of a hydrotrope can be present in the range ofapproximately 0-10000 ppm in cleaning solutions at use concentrations.

Chelating/Sequestering Agent

The composition may include a chelating/sequestering agent such as anaminocarboxylic acid, a condensed phosphate, a phosphonate, apolyacrylate, and the like. In general, a chelating agent is a moleculecapable of coordinating (i.e., binding) the metal ions commonly found innatural water to prevent the metal ions from interfering with the actionof the other detersive ingredients of a cleaning composition. Thechelating/sequestering agent may also function as a threshold agent whenincluded in an effective amount. An iminodisuccinate (availablecommercially from Bayer as IDS™) may be used as a chelating agent.

The composition of a chelating/sequestering agent can be present in therange of approximately 0-10000 ppm in cleaning solutions at useconcentrations.

Useful aminocarboxylic acids include, for example,N-hydroxyethyliminodiacetic acid, nitrilotriacetic acid (NTA),ethylenediaminetetraacetic acid (EDTA),N-hydroxyethyl-ethylenediaminetriacetic acid (HEDTA),diethylenetriaminepentaacetic acid (DTPA), and the like. Examples ofcondensed phosphates useful in the present composition include sodiumand potassium orthophosphate, sodium and potassium pyrophosphate, sodiumtripolyphosphate, sodium hexametaphosphate, and the like. Thecomposition may include a phosphonate such as1-hydroxyethane-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4tricarboxylic acid, and the like.

Polymeric polycarboxylates may also be included in the composition.Those suitable for use as cleaning agents have pendant carboxylategroups and include, for example, polyacrylic acid, maleic/olefincopolymer, acrylic/maleic copolymer, polymethacrylic acid, acrylicacid-methacrylic acid copolymers, and the like. For a further discussionof chelating agents/sequestrants, see Kirk-Othmer, Encyclopedia ofChemical Technology, Third Edition, volume 5, pages 339-366 and volume23, pages 319-320, the disclosure of which is incorporated by referenceherein.

Thickening Agent

In some embodiments, a thickening agent may be included. Some examplesof thickeners include soluble organic or inorganic thickener material.Some examples of inorganic thickeners include clays, silicates and otherwell-known inorganic thickeners. Some examples of organic thickenersinclude thixotropic and non-thixotropic thickeners. In some embodiments,the thickeners have some substantial proportion of water solubility topromote easy removability. Examples of useful soluble organic thickenersfor the compositions of the invention comprise carboxylated vinylpolymers such as polyacrylic acids and alkali metal salts thereof, andother similar aqueous thickeners that have some substantial proportionof water solubility. The composition of a thickening agent can bepresent in the range of approximately 0-10000 ppm in cleaning solutionsat use concentrations.

Bleaching Agents

The composition may include a bleaching agent in addition to or inconjunction with the source of chlorine. Bleaching agents for lighteningor whitening a substrate, include bleaching compounds capable ofliberating an non-chlorine active halogen species, such as iodine andiodine containing complexes, Br₂, and/or —OBr⁻, under conditionstypically encountered during the cleansing process. A bleaching agentmay also be a peroxygen or active oxygen source such as hydrogenperoxide, perborates, sodium carbonate peroxyhydrate, phosphateperoxyhydrates, potassium permonosulfate, and sodium perborate mono andtetrahydrate, with and without activators such as tetraacetylethylenediamine, and the like. The composition of a non-chlorine bleaching agentcan be present in the range of approximately 0-10000 ppm in cleaningsolutions at use concentrations.

Dye or Odorant

Various dyes, odorants including perfumes, and other aesthetic enhancingagents may also be included in the composition. Dyes may be included toalter the appearance of the composition, as for example, Direct Blue 86(Miles), Fastusol Blue (Mobay Chemical Corp.), Acid Orange 7 (AmericanCyanamid), Basic Violet 10 (Sandoz), Acid Yellow 23 (GAF), Acid Yellow17 (Sigma Chemical), Sap Green (Keyston Analine and Chemical), MetanilYellow (Keystone Analine and Chemical), Acid Blue 9 (Hilton Davis),Sandolan Blue/Acid Blue 182 (Sandoz), Hisol Fast Red (Capitol Color andChemical), Fluorescein (Capitol Color and Chemical), Acid Green 25(Ciba-Geigy), and the like. Fragrances or perfumes that may be includedin the compositions include, for example, terpenoids such ascitronellol, aldehydes such as amyl cinnamaldehyde, a jasmine such asClS-jasmine orjasmal, vanillin, and the like.

Antimicrobial Agent

The compositions may optionally include an antimicrobial agent orpreservative. Antimicrobial agents are chemical compositions that can beused in the compositions to prevent microbial contamination anddeterioration of commercial products material systems, surfaces, etc.Generally, these materials fall in specific classes including phenolics,halogen compounds, quaternary ammonium compounds, metal derivatives,amines, alkanol amines, nitro derivatives, analides, organosulfur andsulfur-nitrogen compounds and miscellaneous compounds. The givenantimicrobial agent depending on chemical composition and concentrationmay simply limit further proliferation of numbers of the microbe or maydestroy all or a substantial proportion of the microbial population. Theterms “microbes” and “microorganisms” typically refer primarily tobacteria and fungus microorganisms. In use, the antimicrobial agents areformed into the final product that when diluted and dispensed using anaqueous stream forms an aqueous disinfectant or sanitizer compositionthat can be contacted with a variety of surfaces resulting in preventionof growth or the killing of a substantial proportion of the microbialpopulation. Common antimicrobial agents that may be used includephenolic antimicrobials such as pentachlorophenol, orthophenylphenol;halogen containing antibacterial agents that may be used include sodiumtrichloroisocyanurate, sodium dichloroisocyanurate (anhydrous ordihydrate), iodine-poly(vinylpyrolidin-onen) complexes, brominecompounds such as 2-bromo-2-nitropropane-1,3-diol; quaternaryantimicrobial agents such as benzalconium chloride,cetylpyridiniumchloride; amines and nitro containing antimicrobialcompositions such as hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine,dithiocarbamates such as sodium dimethyldithiocarbamate, and a varietyof other materials known in the art for their microbial properties.Antimicrobial agents may be encapsulated to improve stability and/or toreduce reactivity with other materials in the detergent composition.When an antimicrobial agent or preservative is incorporated into thecomposition, the composition of an antimicrobial agent can be present inthe range of approximately 0-10000 ppm in cleaning solutions at useconcentrations.

Polar Carrier

The cleaning compositions of the invention may include a polar carriermedia, such as water, alcohols, for example low molecular weight primaryor secondary alcohols exemplified by methanol, ethanol, propanol,isopropanol, and the like, or other polar solvents, or mixtures andcombinations thereof.

Polar carrier may be present in the composition in the range of about 10to about 90%, in the range of about 20 to about 80%, or in the range ofabout 25 to 75% by weight based on the total weight of the composition.

Enzymes

The composition of the invention may include one or more enzymes, whichmay act by degrading or altering one or more types of soil residuesencountered thus removing the soil or making the soil more removable bya surfactant or other component of the cleaning composition. Forexample, one or more proteases can cleave complex, macromolecularprotein structures present in soil residues into simpler short chainmolecules which are, of themselves, more readily solubilized orotherwise more easily removed by solutions containing said proteases.

Suitable enzymes may include a protease, an amylase, a lipase, agluconase, a cellulase, a peroxidase, or a mixture thereof of anysuitable origin, such as vegetable, animal, bacterial, fungal or yeastorigin. Selections are influenced by factors such as pH-activity and/orstability optima, thermostability, and stability to active detergents,builders and the like. In this respect bacterial or fungal enzymes maybe preferred, such as bacterial amylases and proteases, and fungalcellulases. Preferably the enzyme may be a protease, a lipase, anamylase, or a combination thereof. Enzyme may be present in thecomposition from at least 0.01 wt %, or 0.01 to 2 wt %.

Enzyme Stabilizing System

The composition of the invention may include an enzyme stabilizingsystem. The enzyme stabilizing system can include a boric acid salt,such as an alkali metal borate or amine (e. g. an alkanolamine) borate,or an alkali metal borate, or potassium borate. The enzyme stabilizingsystem can also include other ingredients to stabilize certain enzymesor to enhance or maintain the effect of the boric acid salt.

For example, the cleaning composition of the invention can include awater soluble source of calcium and/or magnesium ions. Calcium ions aregenerally more effective than magnesium ions and are preferred herein ifonly one type of cation is being used. Cleaning and/or stabilized enzymecleaning compositions, especially liquids, may include 1 to 30, 2 to 20,or 8 to 12 millimoles of calcium ion per liter of finished composition,though variation is possible depending on factors including themultiplicity, type and levels of enzymes incorporated. Water-solublecalcium or magnesium salts may be employed, including for examplecalcium chloride, calcium hydroxide, calcium formate, calcium malate,calcium maleate, calcium hydroxide and calcium acetate; more generally,calcium sulfate or magnesium salts corresponding to the listed calciumsalts may be used. Further increased levels of calcium and/or magnesiummay of course be useful, for example for promoting the grease-cuttingaction of certain types of surfactant.

Additional Surfactants

Additional surfactants may be present in some compositions embodying theinvention. The surfactant or surfactant admixture can be selected fromnonionic, semi-polar nonionic, anionic, cationic, amphoteric, orzwitterionic surface-active agents; or any combination thereof.

Detergent Builders or Fillers

A composition may include a minor but effective amount of one or more ofa detergent filler which does not perform as a cleaning agent per se,but cooperates with the cleaning agent to enhance the overall cleaningcapacity of the composition. Examples of fillers suitable for use in thepresent cleaning compositions include sodium sulfate, sodium chloride,starch, sugars, C₁-C₁₀ alkylene glycols such as propylene glycol, andthe like. Inorganic or phosphate-containing detergent builders mayinclude alkali metal, ammonium and alkanolammonium salts ofpolyphosphates (e.g. tripolyphosphates, pyrophosphates, and glassypolymeric meta-phosphates). Non-phosphate builders may also be used. Adetergent filler may be included in an amount of 1-20 wt %, or 3-15 wt%.

Defoaming Agents

A minor but effective amount of a defoaming agent for reducing thestability of foam may also be included in the compositions. The cleaningcomposition can include 0.01-5 wt % of a defoaming agent, or 0.01-3 wt%.

Examples of defoaming agents include silicone compounds such as silicadispersed in polydimethylsiloxane, fatty amides, hydrocarbon waxes,fatty acids, fatty esters, fatty alcohols, fatty acid soaps,ethoxylates, mineral oils, polyethylene glycol esters, alkyl phosphateesters such as monostearyl phosphate, and the like. A discussion ofdefoaming agents may be found, for example, in U.S. Pat. No. 3,048,548to Martin et al., U.S. Pat. No. 3,334,147 to Brunelle et al., and U.S.Pat. No. 3,442,242 to Rue et al., the disclosures of which areincorporated by reference herein.

Divalent Ion

The compositions of the invention may contain a divalent ion, selectedfrom calcium and magnesium ions, at a level of from 0.05% to 5% byweight, or from 0.1% to 1% by weight, or 0.25% by weight of thecomposition. The divalent ion can be, for example, calcium or magnesium.The calcium ions can, for example, be added as a chloride, hydroxide,oxide, formate, acetate, nitrate salt.

Polyol

The composition of the invention can also include a polyol. The polyolmay provide additional stability and hydrotrophic properties to thecomposition. Propylene glycol and sorbitol are examples of some suitablepolyols.

The compositions of the invention may also contain additional typicallynonactive materials, with respect to cleaning properties, generallyfound in liquid pretreatment or detergent compositions in conventionalusages. These ingredients are selected to be compatible with thematerials of the invention and include such materials as fabricsofteners, optical brighteners, soil suspension agents, germicides,viscosity modifiers, inorganic carriers, solidifying agents and thelike.

Methods of Making the Compositions

The compositions according to the invention are easily produced by anyof a number of known art techniques. Conveniently, a part of the wateris supplied to a suitable mixing vessel further provided with a stirreror agitator, and while stirring, the remaining constituents are added tothe mixing vessel, including any final amount of water needed to provideto 100% wt. of the inventive composition.

The compositions may be packaged in any suitable container particularlyflasks or bottles, including squeeze-type bottles, as well as bottlesprovided with a spray apparatus (e.g. trigger spray) which is used todispense the composition by spraying. Accordingly the compositions aredesirably provided as a ready to use product in a manually operatedspray dispensing container.

Preferably, the composition is adapted for being dispensed using atrigger spray. Alternately, preferably, the composition is adapted forbeing dispensed using a squeeze bottle through a nozzle.

Whereas the compositions of the present invention are intended to beused in the types of liquid forms described, nothing in thisspecification shall be understood as to limit the use of the compositionaccording to the invention with a further amount of water to form acleaning solution there from. In such a proposed diluted cleaningsolution, the greater the proportion of water added to form saidcleaning dilution will, the greater may be the reduction of the rateand/or efficacy of the thus formed cleaning solution.

Conversely, nothing in the specification shall be also understood tolimit the forming of a “super-concentrated” cleaning composition basedupon the composition described above. Such a super-concentratedingredient composition is essentially the same as the cleaningcompositions described above except in that they include a lesser amountof water.

Methods of Cleaning

The present invention aims to provide improved waterpurification/treatment or cleaning compositions and methods forpurifying and/or removing oily particles, and/or contaminants suspendedor dissolved in water. The invention is primarily directed at removingan oil phase from an oil/aqueous mixed phase via foam fractionation. Thefoam fractionation techniques and additives may be used to remove oiland oily soils in any of a number of water purification embodiments suchas clean-up of contaminated water from an oil leak or an oil spill,clean-up of effluent/waste water from Textile Care and food and beverageplants, and restaurants, etc. Another application including enhancedstabilization of foam and increased oil solubilization in foamstructures in applications where foam is desired under greasy soilconditions, such as foam cleaning and pot and pan cleaning.

According to the invention, a water solution in an oil/aqueous mixedphase is treated with an effective amount of associative thickener andif necessary, surfactant so that associative thickener and surfactantare in a ratio of greater than 1:1 on an actives weight basis. Otheracceptable ratios include 2:1, 3:1, 4:1 or even 5:1.

Once the mixed phase has the additives, the oil and oily particles maybe separated from the solution by foam fractionation. In particular, themixture is transferred to a suitable foam fractionation column, throughwhich a continuous bubbling of gas is supplied. In some designs, the airis supplied shooting up. In other designs, the air can be suppliedshooting down then rises up due to buoyance to increase the distancetravelled. Suitable gases for bubbling include air, nitrogen and carbondioxide. The gas bubbles carry the associative thickener/surfactant/oilaggregate as a foam into an overhead chamber that is equipped with amechanical foam breaker to condense the foam. Alternatively, the watersolution is an oil/aqueous mixed phase and can be introduced into a foamfrationator which has a built-in injection mechanism for introduction ofsurfactant, polymer, and air. A preferred design uses a multi-stagedesign to save time.

In general, a foam fractionator (see FIGS. 5 and 6 for example)comprises a chamber often in a cylindrical shape and means are providedfor supplying air to a lower portion of the chamber for bubbling throughwater therein. Air is suitably supplied to one or more air blocks in thelower portion of the chamber. An inlet for water is suitably provided atthe upper end of the chamber. An outlet from the chamber is suitablyprovided at a lower end of the chamber. The fifth chamber suitablyincludes a funnel member at or adjacent the upper level of water in thechamber for collecting waste entrained in bubbles at the surface of thelevel of water. The funnel member is suitably connected to waste. Thefunnel member may be adjustably supported for height variations withinthe chamber of the foam fractionator. Alternatively, the funnel membermay be supported by a float or floats at or adjacent the level of waterin the foam fractionator chamber.

There are several variations in the method of operating the foamfractionator in accordance with the invention that are likely toincrease the efficiency of the oil recovery,

-   -   1. The first method involves adding the surfactant or the        surfactant/associative thickener system in a single shot at the        beginning of the experiment. The experimental results showed        that this method is generally not as efficient as other methods.        However, the simplicity and ease of dosing the active material        is beneficial.    -   2. The experimental results show that better oil recovery is        achieved when the surfactant is added in sequential        additions—i.e. surfactant added initially and then added in ten        minute intervals.    -   3. The experimental results also show that better oil recovery        is achieved when the surfactant and associative thickener system        is added in sequential additions—i.e. surfactant and associative        thickener added initially and then added in ten minute        intervals.    -   4. As stated, better oil recovery is achieved with sequential        additions. It is likely that what is occurring is that the oil        able to fully interact with the surfactant, perhaps forming some        emulsions before the surfactant has foamed off.

An additional benefit of allowing the surfactant to fully interact withthe oil before starting the foam fractionation process is that the watercontent in the foam can be controlled. This would occur as there wouldbe more oil at the hydrophobic/hydrophilic interface.

Also, this change in level of oil at the interface will also control thefoam stability. It is beneficial to have a foam layer that will breakfairly readily after it has reached the collection chamber. It is wellknown that the addition of oil will destabilize foam.

Therefore, the following method will likely increase oil recovery:

-   -   a. Block the air inlet at the beginning of the experiment.    -   b. Start the recirculation, add oily soil.    -   c. Add surfactant. The recirculation will allow the surfactant        to closely interact with the oily soil, perhaps forming some        emulsions.    -   d. Open the air inlet, and allow air injection for foam        fractionation.    -   e. Optionally, surfactant and/or associative thickener after the        foam fractionation has proceeded for a period of time.    -   5. Similarly, the following method including the associative        thickener will increase oil recovery.    -   a. Block the air inlet at the beginning of the experiment.    -   b. Start the recirculation, add oily soil.    -   c. Add surfactant. The recirculation will allow the surfactant        to closely interact with the oily soil, perhaps forming some        emulsions.    -   d. Add the associative thickener.    -   e. Open the air inlet, and allow air injection for foam        fractionation.

Examples of foam fractionators are described in U.S. Pat. No. 70,255,883(particularly columns 11 line 23 through column 33 line 44 and figuresassociated therewith), and U.S. Pat. No. 7,481,935 (particularly column4 lines 44 through column 19 lines 25 and figures associated therewith),the disclosures of which are hereby incorporated by reference herein intheir entirety. Additionally foam fractionators are widely commerciallyavailable from a number of sources including Scientific Associates, LLC.PureShrimpi'm Recirculating Aquaculture System. Foam fractionators mayalso be called protein skimmers.

The present invention will now be further illustrated by way of thefollowing non-limiting examples, in which parts and percentages are byweight unless otherwise indicated.

Example 1 Test Method: Test Method #1:

This method was used in the first set of experiments and used motor oilto approximate a petroleum type oil in the fractionator.

-   -   The foam fractionator was filled with 5 gpg cold water. (From        its dimensions, the volume of the fractionator is approximately        36 gal.    -   Approximately 4000 g of a saltwater-reproducing salt mix was        added to achieve a salinity of 35 g/L.    -   200 g of Holiday brand SAE 30 Heavy Duty Motor Oil was added to        the top of the saltwater solution.    -   The pump was then turned on with the air intake closed. The air        intake tube was inserted into a solution containing DI water and        the amount of chemical for each test. The air intake was then        opened, allowing the chemical solution to be sucked into the        fractionator and the air intake left open after all the solution        is in the fractionator.    -   Samples and observations were taken throughout the testing as        noted for each particular test.

Test Method #2:

This method used crude oil obtained from a refinery.

-   -   The foam fractionator was filled with 5 gpg cold water. (From        its dimensions, the volume of the fractionator is approximately        36 gal.    -   Approximately 4000 g of a saltwater-reproducing salt mix was        added to achieve a salinity of 35 g/L.    -   200 g of crude oil obtained from a refinery was added to the top        of the saltwater solution.    -   The pump was then turned on with the air intake closed. The air        intake tube was inserted into a solution containing DI water and        the amount of chemical for each test. The air intake was then        opened, allowing the chemical solution to be sucked into the        fractionator and the air intake left open after all the solution        is in the fractionator.    -   Samples and observations were taken throughout the testing as        noted for each particular test.    -   The solutions were also compared visually to crude oil standards        in order to approximate the concentration of the effluent        solutions. The preparation of the crude oil samples can be seen        below.

Crude Oil Standards:

Crude oil standards were prepared in the following manner:

-   -   The 1500 ppm solution was mixed in order to fully disperse the        oil in the solution.    -   Each successive solution was made through successive dilutions        of the previous mixture.    -   The amounts for each solution are listed in the table below:

1500 750 375 187.5 93.75 46.875 23.4375 Water 1996.94 0 0 0 0 0 0 SaltMix 58.7 0 0 0 0 0 0 Oil 3 0 0 0 0 0 0 T-Maz 80 0.06 0 0 0 0 0 0Previous Mix 0 200 200 200 200 200 200 Pre-mixed 0 200 200 200 200 200200 Saltwater

Test Method #3:

This method used fresh water and a triglyceride oil.

-   -   The foam fractionator was filled with 5 gpg cold water. (From        its dimensions, the volume of the fractionator is approximately        36 gal.    -   200 g of soybean oil dyed with Sudan IV dye (0.05 g/300 g oil)        added to the top of the fresh water solution. The purpose of the        addition of the Sudan IV is for easier visual observation.    -   The pump was then turned on with the air intake closed. The air        intake tube was inserted into a solution containing DI water and        the amount of chemical for each test. The air intake was then        opened, allowing the chemical solution to be sucked into the        fractionator and the air intake left open after all the solution        is in the fractionator.    -   Samples and observations were taken throughout the testing as        noted for each particular test.        Initial Foam Fractionation Testing with Motor Oil as a        Representative Petroleum Oil:

Several tests were run with various surfactants and surfactantcombinations in the foam fractionator. Test Method #1 was used for thistesting.

The results are summarized in the table below.

Ecolab Foam Fractionalization Data - Jul. 23, 2010, Victor Mann and MikeDeNoma In all experiments below, 1.98 grams of active surfactants(s);200 grams of motor oil; 36 gallons of simulated sea water. Collectedfrom foam: Liquid Oil collected layer Collected per per liquid foam Oilfoam Foam height time layer time time Foam cm cm/min cm cm/min min breakOil layer observations Collected water solution observations A1 LES19.90 2.09 0.25 0.026 9.50 − Incomplete oil layer Clear solution-oilring on sides and oil bubbles/slick on top A2 LES/AO (3:1) 21.05 2.110.40 0.040 10.00 −− Incomplete oil layer Clear solution-oil ring onsides and oil bubbles/slick on top A3 LES/AO (1:1) 17.90 1.79 0.30 0.03010.00 −−− Incomplete oil layer Clear solution-oil ring on sides and oilbubbles/slick on top, though not as many bubbles as A1 and A2 A4 LES/AO(1:3) 19.40 2.10 0.30 0.032 9.25 + Mostly complete oil layer Clearsolution-no significant oil ring, some oil bubbles, and oil slick on topA5 AO ***20.85 2.19 0.55 **0.058 9.50 **++ **Mostly complete oil layer**Clear solution-maybe some oil ring, but barely visible, some oilbubbles, and oil slick on top B1 24-3 NA NA NA NA 0.00 NA NA Slightyellow solution-maybe some oil ring but barely visible, some oilbubbles, and oil slick on top B2 24-3/LS (3:1) *1.95 1.30 0.30 *0.2001.50 NA *Incomplete oil layer **Slight yellow solution-maybe some oilring, but barely visible, some oil bubbles, and oil slick on top B324-3/LS (1:1) *7.90 0.79 0.40 **0.040 10.00 *−− **Complete oil layer**Slight yellow solution-maybe some oil ring, but barely visible,minimal oil bubbles and oil slick on top B4 24-3/LS (1:3) **11.45 1.210.40 **0.042 9.50 **+ **Complete oil layer **Slight yellowsolution-maybe some oil ring, but barely visible, minimal oil bubblesand oil slick on top B5 LS **11.00 2.59 0.45 *0.106 4.25 **++ **Mostlycomplete oil layer **Slight yellow solution-maybe some oil ring, butbarely visible, minimal to no oil bubbles, minimal oil slick on top D124-3/LES (3:1) NA NA NA NA 0.00 NA NA Clear solution-oil ring on sidesand oil bubbles/slick on top D4 24-3/LES (2:1) *5.80 0.58 0.35 **0.03510.00 *− **Somewhat complete layer **Clear solution-oil ring on sidesand oil bubbles/slick on top D2 24-3/LES (1:1) **9.55 0.96 0.50 **0.05010.00 *− **Somewhat complete layer **Clear solution-oil ring on sidesand oil bubbles/slick on top D3 24-3/LES (1:3) **13.20 1.32 0.40 **0.04010.00 *−− **Somewhat complete layer **Clear solution-oil ring on sidesand oil bubbles/slick on top C1 T-Maz20 17.80 4.19 0.35 0.082 4.25 ++Incomplete oil layer Clear solution-oil ring on sides and oilbubbles/slick on top C2 DOSS *3.65 1.62 0.30 *0.133 2.25 **++*Incomplete oil layer **Clear solution-oil ring on sides and many oilbubbles/slick on top C3 T-Maz20/ 17.70 2.53 0.30 0.043 7.00 ++ Mostlycomplete oil layer Clear solution-oil ring on sides and oil DOSS (1:1)bubbles/slick on top C4 S-Maz 20 NA NA NA NA 0.00 NA NA Clearsolution-oil ring on sides and oil bubbles/slick on top C5 S-Maz 80 NANA NA NA NA NA NA NA C6 T-Maz 60 **12.50 1.92 0.35 **0.054 6.50 **++**Somewhat complete layer **Clear solution-oil ring on sides and oilbubbles/slick on top C7 T-Maz 80 **14.50 2.90 0.35 **0.070 5.00 **++**Mostly complete oil layer **Clear solution-oil ring on sides and oilbubbles/slick on top Surfactant Key: LES: Lauryl ether sulfate AO:Lauryl dimethyl amino oxide 24-3: Linear C12-14 alcohol 3 molesethoxylate LS: Lauryl sulfate DOSS: Di-octyl sulfosuccinate T-Maz 20:POE (20) sorbitan monolaurate T-Maz 60: POE (20) sorbitan monostearateT-Maz 80: POE (20) sorbitan monooleate S-Maz 20: Sorbitan monolaurateS-Maz 80: Sorbitan monooleate *= relative advantage **= light relativeadvantage ***= relative disadvantage ****= light relative disadvantageT-Maz 20, 60 and 80 and S-MAz 20 and 80 are commercially available fromBASF Corporation Mount Olive, N.J.The results of these tests show that:

-   -   One pass with a sufficient surfactant system provides roughly an        effluent of 2% oil and 98% water.    -   Seven different surfactants have been evaluated in 25        combinations/concentrations, and some give sufficient results        and some give insufficient results.    -   We consider the 2% oil/98% water effluent not practical, since        the EPA criterion allowing discharge is 15 ppm crude oil in sea        water.        I. Foam Fractionation Testing with Crude Oil and T-Maz 80:

T-Maz 80 was chosen as the surfactant to use for further foamfractionation testing due to its performance in the previous testing aswell as its acceptance by the EPA in products already in use as oildispersants.

The test was performed using Test Method #2. Successive doses ofsurfactant were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 was added.    -   At 10 minutes, a sample of the effluent was collected, and 1.98        g T-Maz 80 was added.    -   At 20 minutes, a sample of the effluent was collected, and 1.98        g T-Maz 80 was added.    -   At 30 minutes, a sample of the effluent was collected and the        test was terminated.        The results showed that:    -   The successive additions of surfactant do not eliminate enough        crude oil in the effluent to achieve the desired 15 ppm or less.    -   Additionally, the concentration after the 3^(rd) iteration is        between 375 and 750 ppm, and likely closer to 400-500 ppm.        II. Foam Fractionation Testing with Crude Oil, T-Maz 80, and an        Associative Thickener:

The test was performed using Test Method #2. Successive doses ofsurfactant and associative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 6.60 g Acusol 820        was added.    -   At 10 minutes, a sample of the effluent was collected, and 1.98        g T-Maz 80 and 6.60 g Acusol 820 was added.    -   At 20 minutes, a sample of the effluent was collected, and 1.98        g T-Maz 80 and 6.60 g Acusol 820 was added.    -   At 30 minutes, a sample of the effluent was collected and the        test was terminated.

Acusol 820 is a Hydrophobically modified Alkali Soluble acrylic polymerEmulsion (HASE) available from Dow Chemical Midland, Mich.

The results showed that:

-   -   Significantly more oil is eliminated from the effluent with the        use of the associative thickener.    -   After 10 minutes, there is less oil remaining in the effluent        than without the associative thickener.    -   After 30 minutes, the effluent is clear, showing there is less        than 23.44 ppm oil remaining in the effluent.        III. Foam Fractionation Testing with Crude Oil, T-Maz 80, and an        Associative Thickener—“One-Shot” Addition.

The test was performed using Test Method #2. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 5.94 g T-Maz 80 and 19.80 g Acusol 820        was added.    -   At 10, 20, and 30 minutes, a sample of the effluent was        collected.    -   At 34 minutes the foam stopped, so a sample of the effluent was        collected and the test was terminated.        The results showed that:    -   The 10 minute effluent is darker than/approximately equal to the        375 ppm standard.    -   The 20 minute effluent is darker than the 187.5 ppm standard.    -   The 30 minute effluent is lighter than the 93.75 ppm standard,        and darker than the 46.88 ppm standard.    -   The 34 minute effluent is lighter than the 46.88 ppm standard,        and darker than the 23.44 ppm standard.        -   Though this has removed a significant amount of oil (and            more so than without the associative thickener) it has            removed less than the previous, sequential addition test.            IV. Foam Fractionation Testing with Crude Oil, T-Maz 80, and            an Associative Thickener—“One-Shot” Addition 1:3 Ratio T-Maz            80 to Acusol 820.

The test was performed using Test Method #2. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 19.80 g Acusol 820        was added.    -   At 10, 20, and 30 minutes, a sample of the effluent was        collected.    -   At 30 minutes the test was terminated.        The results showed that:    -   The 10 minute effluent is lighter than the 375 ppm standard and        darker than the 187.5 ppm standard.    -   The 20 minute effluent is lighter than the 93.75 ppm standard,        and darker than the 46.88 ppm standard.    -   The 30 minute effluent is lighter than the 23.44 ppm standard.    -   This shows that a 1:3 ratio of T-Maz 80 to Acusol 820 is        preferred, and can be effective in the one-shot addition method.        V. Summary of Foam Fractionation Testing with Soybean Oil in a        Freshwater System:

The following testing was performed using Test Method #3. The followingtable shows the results of the foam fractionator testing using SoybeanOil dyed with Sudan IV as the soil.

The results reflect visual observations of the effluent in the foamfractionator effluent tank. The time was recorded when the pink colorfrom the oil started to clear and was no longer visible. Also, theeffluent showed a hazy white cloudiness after the oil was removed—thetime was recorded when this cloudiness started to clear and was nolonger apparent. (The results for each test are outlined in the sectionsbelow.)

Active Material (g) Time (min) cm T- Barely - No Foam Effluent cm/minSurf Maz Acusol DV- Perceptible Solution Duration Level (in level/ RatioConc 80 820 8829 Oil Clearing (min) 5 gal pail) time 1:3 X 1.98 5.9415:00-20:00 22-40 >40 No Data No Data (strong) 1:2 X 1.98 3.9617:30-20:00 23-50 >50 11.3 0.23 (barely) 1:1 X 1.98 1.98 — — 10 6.3 0.631:2 1/2X 0.99 1.98 — — 10 6.5 0.65 1:2 3/4X 1.49 2.97 16:00-18:00 34->44 44 7.2 0.16 1:3 3/4X 1.49 4.455 12:30-16:00 16-35 >50 (slow)15.2 0.30 1:0 3/4X 1.49 0 — — 10:30 11.9 1.13 1:3 3/4X 1.49 4.455 — — 3512.3 0.35The results showed that:

-   -   The 1:3 full conc. T-Maz/Acusol 820, 1:2 full conc. T-Maz/Acusol        820, 1:2 ¾ conc. T-Maz/Acusol 820 and 1:3 ¾ conc. T-Maz/Acusol        820 removed the oil fully.    -   The 1:3 ¾ conc. T-Maz/Acusol 820 had the quickest removal and        clearing times with a good, low effluent oil level.    -   The 1:3 full conc. T-Maz/Acusol 820 and 1:2 full conc.        T-Maz/Acusol 820 had good overall results as well.        VI. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:3 Ratio T-Maz 80        to Acusol 820.

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 19.80 g Acusol 820        was added.    -   At 10, 20, 30 and 40 minutes, a sample of the effluent was        collected.    -   At 40 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 15 min, and definitely no pink        hue remaining at 20 min.    -   The cloudiness started to be perceptively less at 22 min and        definitively clearer but still cloudy at 40 min.    -   Foam was still being generated fairly quickly at 40 min.        VII. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:2 Ratio T-Maz 80        to Acusol 820.

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 13.20 g Acusol 820        was added.    -   At 10, 20, 30, 40 and 50 minutes, a sample of the effluent was        collected.    -   At 50 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 17.5 min, and definitely no pink        hue remaining at 20 min.    -   The cloudiness started to be perceptively less at 23 min and        much clearer at 50 min, but still somewhat cloudy.    -   Foam was barely being generated at 50 min.        VIII. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:1 Ratio T-Maz 80        to Acusol 820.

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 6.60 g Acusol 820        was added.    -   At 10 minutes a sample of the effluent was collected.    -   At 10 minutes the test was terminated.        The results showed that:    -   Foam stopped being generated at 10 min.    -   The pink color denoting oil remaining in the effluent was still        remaining at 10 min    -   The associative thickener concentration appears to be critical        in generating enough foam for oil removal with this level of        T-Maz 80.        IX. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:2 Ratio T-Maz 80        to Acusol 820, ½ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 0.99 g T-Maz 80 and 6.60 g Acusol 820        was added.    -   At 10 minutes a sample of the effluent was collected.    -   At 10 minutes the test was terminated.        The results showed that:    -   Foam stopped being generated at 10 min.    -   The pink color denoting oil remaining in the effluent was still        remaining at 10 min    -   The overall concentration of surfactant and associative        thickener appears to be critical in generating enough foam for        oil removal.        X. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and an        Associative Thickener—“One-Shot” Addition 1:2 Ratio T-Maz 80 to        Acusol 820, ¾ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.49 g T-Maz 80 and 9.90 g Acusol 820        was added.    -   At 10, 20, 30, 40 and 44 minutes, a sample of the effluent was        collected.    -   At 44 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 16 min, and definitely no pink        hue remaining at 18 min.    -   The cloudiness started to be perceptively less at 34 min and        much clearer at 44 min.    -   Foam stopped being generated at 44 min.        XI. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:3 Ratio T-Maz 80        to Acusol 820, ¾ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.49 g T-Maz 80 and 14.85 g Acusol 820        was added.    -   At 10, 20, 30, 40 and 50 minutes, a sample of the effluent was        collected.    -   At 50 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 12.5 min, and definitely no pink        hue remaining at 16 min.    -   The cloudiness started to be perceptively less at 16 min and        much clearer at 35 min.    -   Foam still being generated slowly at 50 min.        XII. Foam Fractionation Testing with Soybean Oil, T-Maz        80—“One-Shot” Addition T-Maz 80 Only, ¾ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 13.20 g Acusol 820        was added.    -   At 10, 20, 30, 40 and 50 minutes, a sample of the effluent was        collected.    -   At 50 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 17.5 min, and definitely no pink        hue remaining at 20 min.    -   The cloudiness started to be perceptively less at 23 min and        much clearer at 50 min, but still somewhat cloudy.    -   Foam was barely being generated at 50 min.        XIII. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:1 Ratio T-Maz 80        to Acusol 820.

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.98 g T-Maz 80 and 6.60 g Acusol 820        was added.    -   At 10 minutes a sample of the effluent was collected.    -   At 10 minutes the test was terminated.        The results showed that:    -   Foam stopped being generated at 10 min.    -   The pink color denoting oil remaining in the effluent was still        remaining at 10 min    -   The associative thickener concentration appears to be critical        in generating enough foam for oil removal with this level of        T-Maz 80.        XIV. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:2 Ratio T-Maz 80        to Acusol 820, ½ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 0.99 g T-Maz 80 and 6.60 g Acusol 820        was added.    -   At 10 minutes a sample of the effluent was collected.    -   At 10 minutes the test was terminated.        The results showed that:    -   Foam stopped being generated at 10 min.    -   The pink color denoting oil remaining in the effluent was still        remaining at 10 min    -   The overall concentration of surfactant and associative        thickener appears to be critical in generating enough foam for        oil removal.        XV. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:2 Ratio T-Maz 80        to Acusol 820, ¾ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.49 g T-Maz 80 and 9.90 g Acusol 820        was added.    -   At 10, 20, 30, 40 and 44 minutes, a sample of the effluent was        collected.    -   At 44 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 16 min, and definitely no pink        hue remaining at 18 min.    -   The cloudiness started to be perceptively less at 34 min and        much clearer at 44 min.    -   Foam stopped being generated at 44 min.        XVI. Foam Fractionation Testing with Soybean Oil, T-Maz 80, and        an Associative Thickener—“One-Shot” Addition 1:3 Ratio T-Maz 80        to Acusol 820, ¾ Concentration:

The test was performed using Test Method #3. The surfactant andassociative thickener were added in the following manner:

-   -   At the start of the test, 1.49 g T-Maz 80 and 14.85 g Acusol 820        was added.    -   At 10, 20, 30, 40 and 50 minutes, a sample of the effluent was        collected.    -   At 50 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        barely, if at all, remaining at 12.5 min, and definitely no pink        hue remaining at 16 min.    -   The cloudiness started to be perceptively less at 16 min and        much clearer at 35 min.    -   Foam still being generated slowly at 50 min.        XVII. Foam Fractionation Testing with Soybean Oil, T-Maz        80—“One-Shot” Addition T-Maz 80 Only, ¾ Concentration:

This test was performed to be a comparison to the ¾ concentrate systemswith the associative thickener. The test was performed using Test Method#3. The surfactant was added in the following manner:

-   -   At the start of the test, 1.49 g T-Maz 80 was added.    -   At 10:30 minutes a sample of the effluent was collected.    -   At 10:30 minutes the test was terminated.        The results showed that:    -   Foam stopped being generated at 10:30 min.    -   The pink color denoting oil remaining in the effluent was still        remaining at 10:30 min    -   The addition of the associative thickener appears to be critical        in generating enough foam for oil removal.        XVIII. Foam Fractionation Testing with Soybean Oil, T-Maz 80,        and a Viscoelastic Surfactant (DV-8829)—“One-Shot” Addition 1:3        Ratio T-Maz 80 to DV-8829, ¾ Concentration:

The test was performed using Test Method #3. The surfactant andviscoelastic surfactant were added in the following manner:

-   -   At the start of the test, 1.49 g T-Maz 80 and 9.90 g DV-8829 was        added.    -   At 10, 20, 30 and 35 minutes, a sample of the effluent was        collected.    -   At 35 minutes the test was terminated.        The results showed that:    -   The pink color denoting oil remaining in the effluent was        present for the entirety of the test.    -   Foam still stopped being generated at 35 min.    -   The addition of the viscoelastic surfactant does not enhance the        foam fractionation of oil.

Without being bound by theory, we believe that two factors are keys inenhancing the foam fractionation removal of oil from an aqueous/oilmixed phase. First, the foam is stabilized. Second, the oil phasepartitions more in the foam than in the aqueous phase.

The proper choice of surfactant is an important factor. A surfactant orsurfactant combination can be chosen with the appropriate foamcharacteristics and regulatory profile. Many polymers can enhance foamstability by increasing foam elasticity. Polymer structures such as theassociative thickeners appear to fit both requirements. The pendanthydrophobic side chains form intermolecular “nodules” stabilizing oildroplets in the foam structure, thereby enhancing their removal.

Methods

There are several variations in the method of operating the foamfractionator that are likely to increase the efficiency of the oilrecovery, and aspects and embodiments can be derived for this invention.

The first method involves adding the surfactant or thesurfactant/associative thickener system in a single shot at thebeginning of the experiment. The experimental results showed that thismethod is generally not as efficient as other methods. However, thesimplicity and ease of dosing the active material is beneficial.

The experimental results show that better oil recovery is achieved whenthe surfactant is added in sequential additions—i.e. surfactant addedinitially and then added in ten minute intervals.

The experimental results also show that better oil recovery is achievedwhen the surfactant and associative thickener system is added insequential additions—i.e. surfactant and associative thickener addedinitially and then added in ten minute intervals.

As stated, better oil recover is achieved with sequential additions. Itis likely that what is occurring is that the oil able to fully interactwith the surfactant, perhaps forming some emulsions before thesurfactant has foamed off.

An additional benefit of allowing the surfactant to fully interact withthe oil before starting the foam fractionation process is that the watercontent in the foam can be controlled. This would occur as there wouldbe more oil at the hydrophobic/hydrophilic interface.

Also, this change in level of oil at the interface will also control thefoam stability. It is beneficial to have a foam layer that will breakfairly readily after it has reached the collection chamber. It is wellknown that the addition of oil will destabilize foam.

Therefore, the following method will likely increase oil recovery:

-   -   a. Block the air inlet at the beginning of the experiment.    -   b. Start the recirculation, add oily soil.    -   c. Add surfactant. The recirculation will allow the surfactant        to closely interact with the oily soil, perhaps forming some        emulsions.    -   d. Open the air inlet, and allow air injection for foam        fractionation.    -   e. Optionally, surfactant and/or associative thickener after the        foam fractionation has proceeded for a period of time.    -   f. Similarly, the following method including the associative        thickener will increase oil recovery.    -   g. Block the air inlet at the beginning of the experiment.    -   h. Start the recirculation, add oily soil.    -   i. Add surfactant. The recirculation will allow the surfactant        to closely interact with the oily soil, perhaps forming some        emulsions.    -   j. Add the associative thickener.    -   k. Open the air inlet, and allow air injection for foam        fractionation.

Example 2

A set of experiments were run using the compositions of the invention.First, water samples were collected and held at 40F post collection. Thechemistry used was a 3:1 blend of polymer: surfactant according to theinvention:

-   -   Polymer—Acusol 820 (45 ppm)

Surfactant—TMAZ 80 (15 ppm)

The composition was added every ten minutes with samples takenimmediately before addition of the composition—four total additions.Sample recirculated for one minute with the composition prior toaeration (3.5 psi sparging tube aeration+Venturi).

Table A below shows the reduction of total suspended solids and totaldissolved solids as well as multiply charged cations at 0 through 4additions of the composition of the invention.

TABLE A 1 2 3 4 Control Addition Additions Additions Additions Barium0.287 0.139 0.0727 0.0555 0.0468 Calcium 26.6 15.9 10.9 8.32 6.54 Copper0.604 0.354 0.171 <0.981 <0.83 Iron 11.4 4.8 2.28 1.36 1.12 Magnesium7.03 3.9 2.43 1.96 1.65 Manganese 0.376 0.195 0.13 0.0854 0.0645Phosphorous <3.37 <3.77 <2.42 <2.45 <2.07 Potassium <33.7 <37.7 <24.2<24.5 <20.7 Silicon 20.2 15.8 15.7 15 14.6 Sodium 280 254 249 243 235Sulfur 6.59 4.58 2.81 2.67 2.93 TDS 956 788 740 690 668 TSS 372 120 6254 40 Zinc 1.23 0.773 0.465 0.327 0.252

FIG. 1 shows the absorbance of the treated water at 0 through 4additions. One can see that after 4 additions, the absorbance units aregreatly reduced. Blue=control, red=one addition, pink=2 additions,green=3 additions, yellow=4 additions.

Additional testing of reclaimed water showed that water initiallytreated with aquaclear still had 29.7 ppm suspended and dissolvedparticles. After 1 addition of the composition and foam fractionationthere were 10.8 ppm, after 2 additions there were 6.6 ppm and at 3additions there were 2.1. The composition was 15 ppm T-mz 80 and 45 ppmAcusol 820.

FIG. 2 shows the captured total suspended solids as passed through afilter. One can see that after 3 additions, the filter isindistinguishable from a clean filter. The foam fractionation removedmultiply charged cations, hydrocarbons, proteins and carbonate.

FIG. 3 is a graph showing FOG reduction with the composition of theinvention at 0 to 3 additions. One can see that the FOG starts at 30.2and after 3 additions is down to 2.9 or 1.4.

FIG. 4 is a graph of absorbance and wave number of the particulates inthe water. After 3 additions, the total suspended solids are reduced tobaseline levels, showing near complete removal of hydrocarbon, protein,and carbonate.

Table B below shows removal of various elements according to theinvention from 0 to 3 additions.

TABLE B 1 1 2 2 3 3 Control Control Addition Addition AdditionsAdditions Additions Additions Barium (ppm) 0.456 0.481 0.382 0.395 0.3110.339 0.214 0.254 Calcium (ppm) 130 135 105 105 101 106 94 94.5 CalciumHardness (ppm as 325 337 262 262 252 265 235 236 CaCO3) Copper (ppm)0.289 0.375 0.186 0.177 0.094 0.11 0.105 0.0815 Iron (ppm) 4.2 4.5 2.912.92 2.42 2.59 2.06 2 Magnesium (ppm) 39.8 41.5 32 32 30.9 32.5 29 29.2Magnesium Hardness (ppm 164 171 132 132 127 134 119 120 as CaCO3)Manganese 0.324 0.345 0.258 0.26 0.245 0.26 0.229 0.228 Phosphorous 5.776.82 3.5 4.18 2.55 3.51 2.68 2.5 Potassium 26.7 27.2 22.7 23.1 21 21.719.9 20.4 Silicon 8.74 9.03 9.22 9.09 8.46 8.85 8.2 7.75 Sodium 915 962778 781 750 789 728 740 Sulfur 264 292 224 213 180 208 260 293 TotalHardness 489 508 394 394 379 399 354 356 Total Hardness GPG 28.6 29.7 2323 22.2 23.3 20.7 20.8 Zinc 0.779 0.82 0.443 0.471 0.218 0.255 0.1420.0815

Example 3

There are a number of foam fractionators available on the market thatmay be used for the invention. Different sizes include 3 liters, 7liters, 26 liters and 130 liter columns. Different formats are alsoavailable. FIGS. 7A and 7B show different designs of foam fractionatorswhich may be used according to the invention. 7A shows a system whereair dissolves in high pressure chamber and has built in airintroduction. Microbubbles are formed with pressure is released. Thissystem requires separate chemistry introduction and mixing. FIG. 7Bshows a system with atmospheric air introduction via suction force. Airbubbles are formed from shearing force in the negative pressure zone ofthe educator. This mechanism can use for chemistry, air introduction andmixing.

FIGS. 8A and 8B shows two example systems each working with thecomposition of the invention. Pump settings were—pressure in =−0.04Mpa/Pressure out=0.175 MPa.

FIG. 9 shows the importance of the compositions of the invention.

Example 4

-   -   FIG. 10 shows the results from the tests below, a graph of        percent transmittance with the associative thickeners of 44 ppm        Rheomer 33, 44 ppm Acusol, and 45 ppm Novethix L-10

Nikuni Pump - 26 Nikuni Pump - 26 Nikuni Pump - 26 0 grain water, litersystem liter system liter system temperature = 120° F. 4500 ppm Soybean4500 ppm Soybean 4500 ppm Soybean oil w/ Sudan IV oil w/ Sudan IV oil w/Sudan IV 100 ppm Turbo Flex 100 ppm Turbo Flex 100 ppm Turbo Flex D AE DAE D AE 45 ppm Rheomer 33 45 ppm Acusol 45 ppm Novethix L- 10 Inlet =−0.02 MPa; Inlet = −0.05 MPa; Inlet = −0.02 MPa; Outlet = 0.4 MPa Outlet= 0.17 MPa Outlet = 0.4 MPa Air from Venturi = Air from Venturi = Airfrom Venturi = 3.7 CFH (1.75 L/min) 3.7 CFH (1.75 L/min) 3.7 CFH (1.75L/min) Time (min) % T Time (min) % T Time (min) % T 0 0.2 1 0 0.2 1 00.1 0.5 5 0.4 2 5 0.2 1 5 0.2 1 10 0.4 2 10 0.6 3 10 0.4 2 15 3.4 17 151 5 15 0.4 2 20 7.8 39 20 4.2 21 20 1 5 25 8.4 42 25 7 35 25 2.2 11 3030 8.4 42 30 3.6 18 35 4.8 24 *immediate white *immediate white*immediate white foam (runny) foam (runny) foam (runny) *pink foam at 3min *pink foam at 3 min *pink foam at 5 min (runny) (runny) (runny)*foaming ceased at *foaming ceased at *foaming ceased at 24 min 30 min35 minFIG. 11 is a graph of the data below, showing percent transmittance overtime for different combinations of polymer and ash.

Without Ash Ash (800 ppm) Time Time (min) % T (min) % T  0 2 20  0 2 2010 2.2 22 10 2.2 22 20 4.2 42 20 3.8 38 30 7 70 30 5.6 56 Polymer =Acusol 820 With Without Ash Ash (800 ppm) Time Time (min) % T (min) % T 0 2.8 14  0 1.4 14 10 5.2 26 10 2 20 20 12.8 64 20 3.6 36 30 15.4 77 305 50 Polymer = Rheomer 33 Without Ash, air = With 20 CFH Without Ash Ash(800 ppm) (9.4 L/min) Time Time Time (min) % T (min) % T (min) % T  02.4 24  0 2.2 22 0 2 20 10 5.8 58 10 2.6 26 2 1.8 18 20 8.8 88 20 4 40 42.8 28 2nd dose at 5 minute 30 9.4 94 30 5.2 52 6 3.4 34 8 4.6 46  0 1.414 10 6 60 10 3.8 38 12 6.6 66 20 7 70 14 7.2 72 30 8.6 86 16 8 80Average 18 8 80  0 1.9 19 20 8 80 10 4.8 48 20 7.9 79 30 9 90 NikuniPump - 26 liter system 1500 ppm Soybean oil w/ Sudan IV 2 doseschemistry, normal dosing 0 grain water, temp = 120° F. Pressure in =−0.02 MPa Pressure out = 0.17 MPa 9 GPM flow Air from Venturi = 3.7 CFM(1.75 L/min) Polymer = Novethix L-10

-   -   Nikuni pump—26 liter system    -   4500 ppm Soybean oil w/Sudan IV    -   1000 ppm Turbo Flex D AE    -   45 ppm Rheomer 33 (3 doses)    -   Temperature=120° F.    -   9 GPM flow    -   Inlet=−0.02 MPa; Outlet=0.17 MPa    -   Air from Venturi=3.7 CFH (1.75 L/min)

Time (min) % T 0 2 20 *stable, white foam (no cleaning) 10 2 20 *stable,white foam (no cleaning) 20 2 20 *stable, white foam (no cleaning) 304.2 42 40 6 60 *added 45 ppm T-maz 80 K 45 9.2 92 50 9.6 96

-   -   FIG. 12 is a graph of transmittance over time for Rheomer 33        alone and after addition of the surfactant per above.

What is claimed is:
 1. A method of improving oil removal and waterpurification by foam fractionation from an oil/aqueous phase solutioncomprising: adding to said solution an effective amount of anassociative thickener in the presence of an effective amount ofsurfactant.
 2. The method of claim 1 wherein said surfactant is presentin said solution prior to the addition of said associative thickener. 3.The method of claim 1 wherein said surfactant is present in a mixturewith said associative thickener.
 4. The method of claim 1 wherein saidassociative thickener is a hydrophobically modified polymer.
 5. Themethod of claim 1 wherein said associative thickener is an acyclicpolymer.
 6. The method of claim 1 further comprising the steps of:adding an effective amount of surfactant to said oil/aqueous emulsion;surfactant allowing the surfactant to interact with the oil, to form anemulsion, thereafter; adding an effective amount of associativethickener to form a mixture; injecting air to said mixture for foamfractionation.
 7. The method of claim 1 wherein surfactant andassociative thickener are added so that the ratio of associativethickener to surfactant greater than 1:1 by weight.
 8. A method of foamfractionation comprising: providing an aqueous/oil mixed phase solutionto a foam fractionator; adding to said solution an effective amount ofan ethoxylated sorbitan ester surfactant, if necessary allowing saidsurfactant to form an emulsion with said oil; adding an effective amountof an acrylic polymer/associative thickener to said surfactant/oilaqueous emulsion; injecting air to said emulsion for foam fractionationand removal of said oil. The injection of surfactant, associativethickener and air can be repeated until water is deemed acceptablyclean.
 9. The method of claim 8 wherein said foam fractionation is toremove an oil spill from a water source.
 10. The method of claim 8wherein said foam fractionation is to clean water for recycling in acleaning system that removes oily soil.
 11. The method of claim 8wherein said amount of associative thickener is 45 ppm and said amountof surfactant is 15 ppm.
 12. The method of claim 8 wherein saidsurfactant and oil are added in a ratio of greater than 1:1 by weight ofassociative thickener and surfactant.